so true.i catch myself thinking of the past and it starts to overwhelm me. but i have hit rock bottom hard enough to know how to keep away from hitting rock bottom again. I used to think that too but now I know it is far from true!
Your are your 'selfish' years. It's a decade to immerse yourself in every single thing possible. Be selfish with your time and all the aspects of you. Tinker with shit, travel, explore, love a lot, love a little and never touch the ground.