Why?

Some moments I really do not like my life. For example, earlier this evening doing stupid bear crawls and wheel barrows up some crazy hill after running in the scorching heat for 45 minutes. Or peeling of stupid wall paper that doesn't want to budge or putting up siding or roofing a house. And unfortunately those moments come up a lot in my life. Also staying up till 3 in the morning to do homework for stuff I don't even care about really makes me irritated. I feel very much like life is passing me by and I don't have the time to enjoy it. I'll never have these days back and never have the chance to go back and redo. When I look back on my youth it will be memories of regrets, and I don't want that to happen. But there's not much I can do about it so I'll just take what I get and not throw a fit I guess.