I just look at him work his body, ab muscles, and figuring things out. Right now, if we leave him on the couch, he will still be there when we get back but he's flipped or toppled over. I realize that having a non-mobile baby is quickly coming to a close. He's almost 6 months old. If he's anything like his big brother, we have about 4-5 months before he will begin to walk. Did you realize I skipped crawling?
Oh well, time flies when you're having fun!