We're all different in how we process things, but I think some people tend to subscribe to the "everything happens for a reason" line of thinking, and then bad things that happen to you are part of your journey and there to give you the opportunity to learn and grow -- and that's a way of looking at it that makes sense of things in that context.
I'm more of the "**** happens" line of thinking -- everyone's dealing with something and life isn't all pleasant and for me, the positive thinking of "it was a challenge that made me grow" simply makes me angry. Life is everything, the good and the bad, and for me, calling the bad "a gift" makes me feel like a hypocrite.
And I am NOT saying that other people are -- I have good friends who see everything in their life as a gift from God and who honestly feel that way. I just don't. I'll handle what gets thrown my way, but don't expect me to like it anymore than I like getting the flu or breaking a leg.
