I understand what you're saying. I always thought, before it happened, that "empty nest syndrome" was a made-up thing, but once it happened, I realized it is a Real Thing. 
And again, sorry, but I wanted to catch up with this, too, even though it's non-lunar. Yes, it's definitely a real thing.
But I'll have to say I envy people like you whose kids are still close by, so you can see them anytime, as well as your grandchildren. Whereas I have one son 400 miles away (Chicago) and the other half a country away (formerly in NYC, now in LA). So I see them only in the summer and around the holidays (well, Jack visits a little more often because Chicago is closer).
Ironically, when they
are here they mostly drive me crazy. They eat so much food, I'm constantly shopping or cooking or ordering pizza. I make some casserole kind of dish that if it were just me would last for two dinners and two lunches, and it's gone the next day. They leave clothes and dishes lying around. They stay up until 4 a.m. and sleep until 2 p.m.
With kids it's so often either not enough, or too much. Having them live in the same city but in different homes seems like the best of all worlds. But both of my kids swear they will not live in Minneapolis when they grow up.
