I've done this too. It's both funny and frustrating at the same time.
When I had my pelvic floor PT, the PT had me get on all fours and rock back and forth and side to side. She said that these motions help strengthen the pelvic floor and back. She said that babies do that to strengthen so they can crawl and walk. So, potentially you could teach your grands how to crawl and walk or your grands can teach you how to get up and walk.
I've been doing those exercises for a few months now and can tell a difference if and when I am on the floor and trying to get up.