Go backpacking or remote camping. You'll find out much easier to wear the same clothes for multiple days. Cause at that point, everything smells like bonfire anyway lol

For me it depends. If I wore a shirt just to go out and grab my mail, I’ll probably wear it again. Quick trip to the grocery store when it’s not hot and I didn’t sweat? Maybe wear it one more time or use it for getting the mail. If I wore a shirt all day, leaned or sat on public furniture that likely isn’t cleaned regularly (i.e. cinema seat, restaurant chair, plane seat), or was in a crowded place in close proximity with a lot of other people (i.e. concert); that’s definitely one wear and goes straight for laundry when I get home.

No. Personally I'm still able to do that but when I do I kind of feel like I'm doing something I shouldn't have.

I have a compartment in my closet where I put all the shirts I've worn but I feel still are clean. Unless they smell bad it doesn't really matter imo.