Agree with most comments. Addiction as a field of study is absolutely
HUGE! Especially research in the past decade or so has proven that there is a ridiculous amount of variables and influences which lead to "addiction"! It is in no way as simple as, "somethings addictive" > "person becomes addicted", or "a person is 'weak'" and hence can become (easily) addiction!
There are so, so many variables. Studies have shown a few things - generalisations I'd say. Thing such as one has a higher risk of becoming addicted if from say a lower SES for instance. Or if there is wide-exposure/easy acquires to a substance from early childhood. But like I said, these are generalisations and there is
always (and often many tbh) exceptions to these! Having said this, there is a strong evidence that basically the cause of addiction is most definitely multi-factorial - physical, psychological, genetic, environmental, etc. No one has (or ever will imo) been able to attribute it to one specific cause.
Even down to the definition of the word "addiction" cannot be well, clearly defined. One most certainly cannot limit it to drugs! Or realising within someone's "addiction" the differences aspects such as physical addiction, as a posed to mental addiction. Or even, and I'm sure many people on BL who has gone through it, would attests that treating the physical aspects - maintenance programs, treating WDs, titration to ween them off - are a quite small part of dealing with an addiction.
.....
Folks who are more resistant to becoming addicted to some drugs
....People seem more genetically susceptible to not only drug addiction, but addiction in general......classic case of nurture vs nature.
I agree with you, Nozphexezora, to an extent. But personally I think it goes much deeper then that. And imo it's this which make it such an interesting/exciting field to study (and what my Master thesis will roughly be on :D )
you may think this but you won't know your addicted until your addicted, if your are immune to addiction then i envy your genes but go on a two year opiate binge and let us know how your feeling
I totally agree with the "not realising it until you are". Tbh, I've went through it myself, and see many, many friends go through it also. However, I understand what you're trying to say, but I think there's a better word we could use then "immune". Maybe it's just me but when I hear that I think that for people who
aren't "immune" are somehow weak(er) or inferior somehow.

The factors involved which may/not cause someone to become addicted has no reflection on how strong (physically nor mentally) that person is.
.....
Ive smoked cigarettes on and off for years but never felt addicted.
Surely someone else can relate?
Most definitely! In my case, I've
tried cigarettes (a number of times in fact) and to this day I absolutely cannot in any way (personally) find any thing about them which would make me want to continue ..... it's just me - as "weak" an argument that maybe. lol.