The good times, because they'll keep you going.
The bad times, because they'll make you stronger. They'll help you to appreciate the good when it's handed to you, rather than overlooking it and understanding later what you neglected to realize in the moment. That's a drag.
Little imperfections, because they characterize the people you love. Those close to you are defined, beautifully defined, by their imperfections, and what may annoy you at times will be the things you remember when you've lost them. When you realize that these things weren't as irritating as you believed, that they made that person who they were. Quirks matter.
Remember that even though things aren't always going to be in perfect order, there will always be something to look forward to; you just can't see it right now. After all, we can't all be psychic.