I'm on a kick right now. I do this all the time with clothes. All I want to wear is tight jeans, short boots, and then either a tee shirt + blazer, or else a button-front shirt + sweater/sweater vest. I seem to need a collar these days! And I can't seem to motivate myself to wear anything else -- haven't worn a skirt in a month, for example. I love how a pencil skirt looks, but I'm just not reaching for them.
Maybe it's the cold.
I do this with other things, too -- I'll eat the same thing for lunch every day for a week, or play music by the same artist, or read every book by the same author. Is it just me, or does everyone do this?