Cars.

Jack loves cars. He plays all day with his cars. Almost every time we go to the store, we end up with another car. Jack now has quite the collection.

Then one day I was putting something away in one of Ben's drawers and found this:

I started laughing. I asked Ben why he had those ones in his drawer. He said they were really cool and he wanted to have those ones to play with when he and Jack play. I laughed again. What a fun dad.