Where Does The Time Go? Seriously Where?

My mom is in town visiting this week. Which is awesome. She's really low-key, and has been here enough times that she doesn't want to go see the Statue of Liberty either, she only wants to do cool stuff like going to see the Imax movie about the Mars Rovers, which is what we did yesterday.
Also, she loves to go to really good restaurants, so I get to go to all the places I read about but am too poor to go to on my own. Currently, I'm trying to talk my stomach into digesting faster so that I'll have enough space for brunch.
The odd thing about her visiting, though, and it's something I notice any time anyone is visiting, or I'm visiting anyone else, is how hard it is to fill up the time. I mean, we plan what seems like a full day's worth of activities, and when we finish doing them, we're tired and ready for it to be dinner time but it's only 3:30.

What it's made me realize is how much of each day I spend doing absolutely nothing. And not the kind of nothing you can share with someone else over coffee and chit chatting. I'm actually not sure what kind of nothing it even is.
Some of it has to be TV watching, certainly. Our TV connection has been broken all week and since mom's been around, we've both been too lazy to call Time Warner and get it fixed. I don't think of myself as a big TV watcher--we don't have cable, and I mostly just watch maybe an hour a day of stuff that was TiVoed or on DVD--and yet I can feel its absence when I can't watch it.
What the rest of the time is, I'm not sure. Reading, maybe? Playing on the internet? Staring blankly off into the distance? I know it's not playing with the cats, because they don't let me slack on doing that. And it's definitely not cleaning. It makes me a little worried, though--why am I spending such a large proportion of my days off doing something that I can't even figure out what it is? Am I some kind of ultra lazy lump of a human being?
Whenever Frank's folks come to visit, his mom always asks, "What would you guys be doing right now if I wasn't here?" and I never have an answer that really makes any sense. “Sleeping” seems like a rude answer (they like to get up early) but seriously: what would I be doing if she weren’t there? It's a mystery.
I guess we all spend a huge amount of our time doing small, unquantifiable tidbits, like walking around, reading something inconsequential, talking on the phone, putting away the dishes, making lunch for the next day, folding laundry, painting toenails, re-setting the wireless router, sucking in your stomach in front of the mirror, bitching about the mail being late, going to the gym, deciding which movie to see, stopping in at the comic shop to browse, fiddling with the stereo, deciding what to wear, taking vitamins, playing solitare, etc.
It takes a visitor to shake out the interstitial puttering and show you how much time you spend actually doing anything. And when you do see it, it's sort of frightening. Is that wasted time? Or is it essential to mental health? Think about how tiring it is to have even the best, most fun and laid back guest, or to go and visit someone--are those fifteen minute chunks of down time an important part of how people function? I'm not sure.
I do know that between Frank and I we can putter away hours without even really noticing. And lord knows we're bastions of mental health. Maybe I should start keeping a timesheet or something. That way, I could at least answer his mom's questions honestly, instead of shrugging and saying "Eating?"