I am a year younger than your son, so I still have a long, long way to go before I feel the thrill of thinking about being a grandfather someday, I guess it must be an amazing thing for you and, I give you some incredible congratulations in case I can't give them to you when the exact moment comes.
My uncles are 58 and 69 (I was raised by them) and when they see their granddaughter they are incredibly happy, they never seem to get tired of being happy with a baby, hopefully, you can receive that happiness at some point!