[mumblemumble]

To add one more possible partial explanation to the list:

Back when I wore a fitness tracker, I typically didn't bother to put it on when I was staying home, including work from home days. It stays on the dresser next to my wallet, which doesn't get put in my pocket when I'm staying home.

I am going for long walks several times a day, in order to ensure I'm getting my exercise. I'm just not bothering to bring anything other than my house keys and maybe my cell phone when I do it.