Well sooner or later you won't be able to get by on 4-6 hours of sleep, your shitty treatment of your body will catch up to you, and you'll enjoy more time just sitting alone than hanging out and drinking with friends. I had the mentality you do, I looked, felt, and acted young. Not sure when exactly it hit me that I'm not that young anymore. You're only 29, so you have a while before you know what I mean.