[catchnear4321]

> I’m in my early 30s right now. I can feel my brain waning here and there--things that I used to pick up quickly are now taking a long time to settle in. I'm wondering why that is.

“One more new thing” is relative. You aren’t starting from the same position this time as the last, or the first.

That’s a good thing.

This internet stranger suspects what you’re calling intelligence is maybe something else. Rest? Motivation?

Don’t forget that your brain isn’t in a vat. (Probably. Maybe. No promises, not getting all philosophical here.) Take care of the whole organism.

[BigHatLogan]

You may be onto something here--I definitely have slipped in taking care of the whole organism. My sluggishness might be a symptom of that.