Actively pursue girls and recreational drugs more than you are.
And recreational drugs? Learn to deal with life on your own without having to rely on crutches. I've seen too many people destroy their lives with drugs (including alcohol) and many more who need a hit/taste/boost/shot in order to deal with the stresses of life.
For the OP: Don't trust people who tell you drugs are bad when they haven't used them extensively. There are lots of ways to hurt yourself. I've seen plenty of people hurt themselves with drugs, but I've seen more of them hurt themselves in cars and on bikes and with crummy jobs. But don't over-do the drugs thing. And don't do drugs if you're not interested.
If he is telling his previous self to do them, he must have found something he enjoys in them. Judging by the average HN user, I doubt he's ruining his life with them and is instead viewing them as an alternative experience to learn rather than crutch to hide.