Don't expect life to be all happy or all sad. That's just plain and dull. Life has its colors. To respect and even deserve the good ones you need to go through the bad ones. If I found a book about life to guide us every step to make sure that things don't go south, would you want it? I sure would read that once and dump it in my trash, Why?
Coz damn sun! I like surprises, I like pain, I like sadness too, not because I enjoy all of them but if not for pain they cause I would never know what happiness truly means. With each moment we spend, there is a thing or two to learn. Live the way you like, make mistakes , learn and grow. After all this is your world too. Remember that!