Today's puzzle reminds us just how extra everything has been recently. You know what you can't have a ton of at once? People, that's what. You can't have so many of them. Not even ten. So stop hoarding all the people, people.
Right, so today's revealer, 39A: "I'm deeply indebted" ... or a hint to the ends of 17-, 25-, 51- and 64-Across (ITMEANSALOTTOME) gives a literal twist to the last words of each of the other theme answers: each one is defined as "a lot." The best of these is SEATTLESLEW, because the second part of the horse's name is actually a simplification of "slough," which doesn't have anything to do with a large amount of something, and because it's a great answer. PAPALMASS and BATTERYPACK are neutral, and SCRAPHEAP is too close to the twisted definition.
Meanwhile, the rest of the puzzle has some nice long answers in it, such as THENATURAL, an old favorite of mine (the movie that is, not the novel, which I did read years ago, and I think enjoyed) and GULFSTATES.
MYOPES was a tough get for a Monday. Or really any day. I mean, I rarely go about describing myself and my wife as a couple of myopes.
In any case, if you're stuck at home, it's time to break out the Sambuca, as we did last night, and shout SKOL!