It isn't a "practical" thing, it is a mental thing. "flossing my whole mouth feels overwhelming, so I'm not going to do any of it", vs "I just need to floss a single tooth, that is easy". Sure "just grow up and do it" sounds nice, but learning to build habits that generally feel unrewarding when starting out (e.g. working out, learning instrument), is extremely difficult for some people (e.g. me).

It's a bit strange that something that takes less than two minutes can seem so overwhelming, yet we've all been there.

For me it is the chore factor, the feeling that it's something bothersome that has to be done. One way around that I've found is to convert it to a desire - saying to myself "I deserve clean, healthy teeth" is enough motivation, for me, to pick up the floss. Similarly, "I deserve a clean, tidy home" gets me picking up the vacuum and mop, "I deserve a healthy body" is a useful mantra for eating well and exercising.

Very true. For me, it is the feeling of 100 small 2-minute things. I find myself looking how to get out of as many as possible.

To me it goes like this; I just did it yesterday, there’s nothing there to get out. So I’d forget about it for another week.

Yes I hated it and yes I’m exceptionally stubborn :)