Alcohol
Actually I have started drinking really late. At the age of 20/21... I was always the one who didn't drink at parties etc. My friends said that I'm so boring because I don't drink. That was how I started drinking. A way to feel "interesting" and get away from myself. I always had/have low self esteem and from that moment on when I was drinking I felt different. The old me was gone and I was a newer, "cooler" and funnier guy. I wasn't actually drinking too much. It's just that I get really easily and fast drunk. But recently, after I have drunken, I felt so bad and had to throw out. That's when I realized that I had to stop for a while. I pondered why I started drinking in the first place. A get away car from my insecurity, boreness, trying to be cool no matter what the consequences are... Before every party I have been drinking drinking until I was drunk so that I could meet with the dream boy of dream or have some hook ups. in nutshell so that I will be more attractive. I know it sounds silly. But a lot of studies have proven that alcohol boosts your confidence and makes you more attractive.
Now I try to cut my alcohol consumption... I am cool in my own way as well :)
Have a nice day :)