I wouldn't say I'm "successful" but I'm getting there.
I was a daily pot smoker by my senior year of High School, I never had good grades even before then, but my interest basically went from slim to none in that year. After High School I took a class to get a MCSE certification and a few others. Basically I went to school to become a network engineer. Well, about that time I found DXM, Robotussin to be precise. I started using DXM just about every day, if not twice. This lasted about 6 or 8 months and I did not pay one bit of attention to my class through the whole time. So, needless to say, I don't have a MCSE certification, nor am I a network engineer. I wasted $20,000 on a loan that now my mom is paying off for me since I don't make enough money to myself. The interest on that loan is so high that in almost 5 years of paying on it, never missing a payment, we have not even TOUCHED the principle. In fact, its gone up
Anywho, after that, I got a bit worse with the DXM when I found online pure powdered sources. Lost a car, and a job, and just fucked around for a good year or year and a half.
After all that I quit the DXM and started to get on the right track a little bit, but I fell back into a lull smoking weed all day every day. My mother kicked me out of the house cause I didn't ever do anything when I was 18. I lived over a friend of mines house during that time and all we did was smoke, drink, hustle to get more weed, and whatever other drugs could be had.
About 2/3 of the way through living at my friends house I got tired of being a fuck up and being depressed all the damn time because of being a fuck up. So I got a job, albeit part-time and just a retail position, to boost my self-esteem. It helped and I felt a little bit human again, instead of a lazy stoner. Around 5 months into this job, a different friend than the one I was living with introduced me to OxyContin. Later the same guy would get me a job with his dads steel fabrication company. At first I didn't think much of OC's, they were fun but nodding out like that could only be done at night to me, since I almost always fell asleep. Then the cold Baltimore winter hit that steel shop. GOD DAMN was it cold. I figured out that Oxy REAALY helps working in the cold

. So from that point I just slipped down the slippery slope of opiate addiction, until about a year and a half to two years later where I am now.
Between being introduced to OCs and now, I've held 3 or 4 jobs. One being the metal shop, which I worked at for over a year. Most of you already know how opiate addiction works, you use rarely at first, then a little more, then a little more.... well I found myself being sick every 3 or 4 days, running out of money, pawning shit, stealing, whatever. Eventually I got sick of living the "junkie lifestyle" and got on Suboxone. Now I'm down to 1mg every other day or so, I try not to use the sub every day because I don't exactly get it from a doctor, so the supply isn't unlimited. But now I manage a decently sized warehouse, and I have a reliable car. I feel much better about myself as far as "success" goes.
However, overall, I would say that I have
not been a very successful drug user. I'm sorry for the long ass post, but I wanted to explain how drugs can take you to the bottom time and time again. Even when you think things are turning around, you have to keep working for it to make it out. I tend to agree with Synto_ on this subject. I don't think that its possible for *most* DAILY users to maintain a "normal" life for too long. Eventually your priorities change and you focus on whats important to you. As an addict, that is drugs.