[__xtrimsky]

My two cents:

Try meditating (specifically with the HeadSpace app if you own a smartphone). Meditating helps you concentrate on the present instead of thinking of the past. For example when I take a walk outside, it helps me appreciate it a lot more even if its cold and uncomfortable. And I don't spend time thinking of useless stuff like I should have worked more at school, or I should have done this and that.

Now you can try this app for free, but I think after 10 courses you have to pay for it. I have a 3 months trial coupon if you want, just contact me through my personal website and I'll send you a coupon: http://andrei.pervychine.com