@Jabberwocky, this is a brilliant question and I'm surprised that way more members haven't contributed to this thread.
For me, the first substance I tried was cannabis, this was way back in 1988.
I believe it was because of two reasons, firstly I was just plain curious and secondly I wanted to be part of the :cool" crowd and all the cool kids were smoking pot.
I believe it was simply a combination of these two factors for the first few years of my substance use, and of coarse, the fact that I loved how cannabis made me feel.
The freedom, or perhaps escapism was amazing, every time I smoked it was like an adventure to somewhere totally new and exciting.
My substance use stayed exclusively with cannabis for about the first year, from there the next experiment was with alcohol.
My first few experiments with alcohol yielded mixed results, which I think is pretty standard for someone in their early/mid teens, sometimes it was great, suddenly I went from introvert to extrovert and could approach total strangers and begin a conversation, something I could never do without alcohol, as much as I loved cannabis I was still an introvert under it's influence.
However I soon discovered alcohol could make you feel terrible if you had a bit too much and I distinctly remember the first few times I made myself sick and spewing my guts up and wishing the world would stop spinning...not fun at all.
Then in my later teens I began experimenting with lsd and mushrooms, both of which could easily go either way, if I was with the right people and in the right environment they could be great and highly enjoyable, but if I was not with the right people and in the right environment they could be rather scary.
For the most part however, both my lsd and mushroom experiments were again very enjoyable adventures into unfamiliar and undiscovered territory.
Things continued like this until I was about 17, by this time I was smoking pot daily and it had progressed to the point where I seemed unable to enjoy myself unless I was stoned, I got expelled from high school at this point for reasons I would prefer not to elaborate on here, and it was at this point things took a turn towards a less positive/exciting experience and started to become more rebellious.
I was still smoking pot everyday, however it was at this point I started smoking cigarettes as well, something I believe was really more of a rebellion than enjoyment.
I started experimenting with delerients and as well as lsd and shrooms was going on regular diphenhydramine trips.
I got a job within a month of getting expelled from school but lost that because I had now started using inhalants, I would soak a rag with paint thinner and take it into the toilet and huff on it, I lost my job because on one of my frequent trips to the toilet I went too hard and knocked myself unconscious, the boss found me on the toilet floor and of coarse this resulted in me losing that job.
So now things were starting to get out of hand, my parents didn't know what to do, I had a stable family life and they could see no reason why this was happening and it was certainly not their fault, they thought that maybe I needed something I could put my energy and mind to in a positive way so we decided maybe a musical instrument would be the answer, so they bought me a set of drums.
I spent about 18 months going to drum lessons and really taking the drums seriously, they must have thought that this was going to be the magic bullet, of coarse they were unaware I was still smoking pretty much daily and still using lsd whenever possible.
So at the end of my teens I had become pretty good on the drums so the logical next step was to join a band, surely getting into the music scene during the 1990's would keep me away from drugs!
So I got myself into a band, the music I loved at this stage of my life was grunge, soundgarden, pearl jam, alice in chains, nirvana and the like, surely there was no danger here, those sort of serious musicians wouldn't be drug users and getting into a grunge band in the 90's would keep me away from drugs....surely.
So on the third of May 1994, which was the day of my 20th birthday I tried heroin for the first time...nothing to worry about there...
So now I was smoking pot everyday, my lsd and mushroom use had mostly ceased as had my use of inhalants and delerients, along with alcohol, within a few months of joining my band I had almost stopped using all of those substances, I had to, because now every cent I had was going to my blossoming heroin habit.
I believe my first use of heroin was again, predominantly out of curiosity, plus the members of my band were all older than me and they all seemed so cool, and I wanted to be like that.
So this post is becoming rather long, so for the sake of brevity I will summarize things a bit at this point.
After my first taste of heroin it was a, where have you been all my life moment, and I was properly addicted within a few months, first I started pawning things and once I had pawned basically everything I owned to finance my habit, which in the end included my drums, I hit rock bottom, at least that's what I thought at the time.
Losing my drums obviously resulted in my being asked to leave the band, which is putting it politely, so I sucked it up and came clean to my parents.
They were shocked, as you can imagine, but my parents are amazing, and they allowed me to move back home and get my shit together.
I tried hard to do just that, I really did, and for a while it looked like I was going to succeed, I cut out everything other than cannabis, I went to my family doctor with my mum and told him everything and he generously gave me a script for diazepam and flunitrazepam, my habit wasn't shocking so these helped me tremendously, I still spent a day or two sitting on the floor of the bathroom and spewing into the bath, my mum sat beside me the whole time, which gave her a crash coarse into the mess I had gotten myself into.
I lasted a few months living at home but eventually I busted and moved out again only to land right back where I had left off with staggering speed, things progressed as you would expect and by 1997 I found myself in prison, I spent 1997, 1998, 1999 in prison and got out December 1999, of coarse now I just had better connections and I had a needle in my arm on the first day out.
I still had over two years of parole to get through and as I had a full habit going within a few months of getting out I knew I had to do something otherwise I was surely going back to prison, as it was I would have gone back if it wasn't for my amazing parents saving me again, I had a urine test coming up which I would have failed so I reached out to my dad and told him everything, he came around and pissed in a cup for me which allowed me to give a clean urine and avoid going back to prison again.
At this point I went on the methadone program, that was the year 2000 and I am still on it today.
The methadone turned my life around and allowed me to get through my parole period and I never went back to prison, however, even though the methadone has kept me from getting out of control on heroin I have battled with addiction to various other substances, crystal meth, ghb, cocaine, mainly though, my doc are downers, so benzodiazepines have been my biggest issue, something which I still struggle with today.
Recently I have been talking to a psychologist to try to get to the bottom of this exact question, why, why do I still struggle with this after 37 years and counting.
My psych has diagnosed me with a complex ptsd as well as gad and of coarse sud, all in all though I wish I had a better answer.
If I am being honest, with certain substances there is certainly a degree of simple enjoyment, however why is it that I cannot control my use, why does it always control me....I wish I knew.
This post has been cathartic so thanks to
@Jabberwocky for asking such an important question, and thanks to anyone who has taken the time to read all of this.