Life is like a box of chocolates...
Yes, that's a joke, but it's also my serious answer. Poop happens. That's life. I have some great days, some horrible days. I'm not a very "reflective" kind of person, so maybe I'm the wrong person to ask. Every day is different. Just because today was bad doesn't mean tomorrow will be. Just because tomorrow was good doesn't mean the next day will be.
Another analogy I'll use...from an old movie. I'm not a movie person at all, but this sort of sticks in my head. It's from the '80's movie "Parenthood". There's a scene where one of the characters (was it Steve Martin's character?) asks the grandmother (who is very elderly) how she managed to get through all these trying times in life. She goes on to describe how life is sort of like a roller coaster. It goes up, it goes down. You have to learn to enjoy it all, as it's a thrilling ride, and that she enjoyed that far more than the merry go round, which just went in circles...or something like that...that's the premise of what she's saying, I don't recall the specific lines. I completely agree with that philosophy.
EDIT: Google is my friend. Here's the exact quote from the movie Parenthood:
Gil has been complaining about his complicated life; Grandma wanders into the room]
Grandma: You know, when I was nineteen, Grandpa took me on a roller coaster.
Gil: Oh?
Grandma: Up, down, up, down. Oh, what a ride!
Gil: What a great story.
Grandma: I always wanted to go again. You know, it was just so interesting to me that a ride could make me so frightened, so scared, so sick, so excited, and so thrilled all together! Some didn't like it. They went on the merry-go-round. That just goes around. Nothing. I like the roller coaster. You get more out of it.