I am the Kat that Walks By Itself

It's so easy to just do it and veg out at the same time. And I don't have to be stuck in my sewing/craft room, because knitting/crocheting are so portable. I can even do them when I ride in the car.
Exactly! One can do it in the bus. One can do it while visiting relatives and still carry on a conversation. One can do it while waiting for stuff.

Also, for myself, I find the fiddliest part of sewing is altering the pattern and cutting out the pieces, so doing that ahead of time and stashing them until I'm ready to do the project helps.
True, but one still needs to set aside a certain amount of time and space to do even that, so it doesn't really help.

I find the best way to keep interested in keeping on with something like sewing or knitting or crocheting (or any other craft for that matter) is to stretch myself by occasionally trying something I've never done before.

It's been interesting to notice the way I've been entering into crochet, because it highlights how I tend to approach craft in general (though some crafts frustrate me because I'm unable to use this approach).

Step 1: Read how-to books (and other how-to documents) and teach myself the basics.
Step 2: Practice the techniques by following patterns.
Step 3: Throw away the patterns and make up my own. Never do the same thing twice.
Step 4: Continue to research new techniques and add them to my repertoire.

Sewing frustrates me because I don't know how to make up patterns. Origami frustrates me because I haven't managed to master the basic techniques. Beading doesn't frustrate me because I never have the same beads twice, so every necklace I make is unique.