One guy says "old age is like being punished for a crime you didn't commit." I think it's the best thing that ever happened to me. Most of it is like a really long movie with only "impossible" events intervening in a mainly predictable/boring plot.
In Madrid there are a lot of benches, at least in the blocks around here and most of those downtown and all Plazas. I sit on a lot of them and watch the endless parade that has lots of my favorites, babies in strollers, rolling by powered by proud parents/grandparents/siblings.
Eye contact is something we have instincts but not much discussion about and between adults the contacts seldom last over two seconds. Babies can lock on to you for as long as they can see you, going to great measures to twist as they pass. If their pushers stop to window shop, you get to play a lot of peek-a-boo with them. Rarely will a baby fret/cry on seeing this old guy staring with a big smile. They will blink with you and laugh if you stick out your tongue, etc.