I get pretty frustrated when someone walks slower than me and keeps lurching back and forth so I can't overtake. Idk why, might miss bus maybe.
I don't say or do anything, though sometimes I nip onto the road or between some tight terrain to overtake
Yeah that's just... you're annoyed. An involuntary feeling of impatience. I don't think this is a moral failing since you don't do anything rude to them, you just politely and silently wait until you can find a way to overtake them that doesn't inconvenience them. Do you feel bad when you pass slower traffic on the freeway?
Just watch it, I suppose. Don't let it turn into something worse.