Mainly because of anxiety, depression, and to be sociable. I use to rarely go out, then I discovered alcohol, and thought I found the miracle cure I've always been looking for. I use then would go out all the time, often times numerous times a week, but it had to be somewhere where alcohol would be.
This "cure" later turned into a full blown addiction taking me back to even worse than square one with out of control anxiety, depression, and social anxiety.