It is because of:
a. peer pressure?
b. early exposure to it?
c. social influence?
d. the dream of winning big and have a good and better life?
e. to cope with stress?
Unfortunately, I started gambling due to none of the above. I've been exposed to gambling since I was in my first year in Junior Secondary School, but I didn't gamble until I was in my last year in university. This proves that I didn't gamble due to any external factors/reasons, but just wanted to gamble. I think it was just for the fun of it then, and not for the money.
Of course, I started with football betting, and it was successful for me before I quit it since I didn't have interest anymore for no reason. I later continued many years after, which makes gambling not to enter me as such till today.