I was always so curious how different my kids would be when we started down the road to having children . I have a 4 year old and 3 month old, both boys. So far the big differences:

* LO1 is high sleep needs, LO2 is way on the low end. A 30 minute nap is his thing
* LO1 had zero interest in putting anything in his mouth, ever. LO2 already wants everything straight to his mouth and has to have a pacifier.
* LO1 was always on the low end of the curve physically and laid back. LO2 is way ahead of the game by starting to roll at 12 weeks and is so active!

Obviously there are physical differences, but what big differences did you see or have been interested to see with your kids?