Check out this hilarious link 36 Reasons My Kids is Crying. You really can't help but laugh out loud at some of these pictures. I think it accurately depicts how crazy life with toddlers can be. They can be extremely unreasonable and picky.
I would like to add to this list from my own personal experience a few things that recently made my kids cry (sorry I only have one tantrum picture)
-they could hear the plane but not see it on cloudy day
- the rottweiler she really wanted to pet didn't like kids
-we broke her kinder egg in half to get toy out
-she couldn't climb the playground with rocks in each hand (didn't want to let go of rocks)
-wouldn't let her eat green skin on watermelon
-wouldn't let them use bag of stinky diapers as a pillow