You can't really understand why someone would want to take drugs unless you're in that situation yourself.
For almost 2 years I was on drugs because it made me feel better. It made me forget about my problems. All I saw were the benefits, until I got addicted. Now I'm thinking a little more clearly. It's amazing how much more happy I am now that I'm off it. When I was on drugs I thought I needed it to be happy, but it turns out it was the total opposite. I'm a lot happier now and I'll never have a good enough reason to go that way again.
Drugs don't make your life better, but when you're on drugs, you believe the drugs are making your life better, when all they're doing is making it worse. So really, all they're doing is preventing you from seeing the damage they cause.
But yea weed should be legal. It's stupid. Weed isn't any worse than alcohol.