Congratulations George! Soapweed is right. The rewards of spending time with little kids are great, and I believe the kids, right from birth, benefit at least as much as we grand and great grand parents do.
A warning: having spent over 8 hours with a two and a half year old yesterday, and me being 77 (for four more days) it does take time to recover! She was very good, and even slept for about three hours after we spent about that long outdoors washing lawn furniture and other 'garden hose jobs'. Quality time and LOTS of conversation wore both of us out. It is surprising how much entertainment value just a trickle of water from a hose, a couple of small buckets and a few plants in pots can have for a tiny little gardener! At over 100% before noon, there seemed no danger of overwatering those plants.
Not sure if you have older grandkids, George, but am sure every one with be uniquely special for your family. Get set for the best time of your life!
mrj