Hmmm. I also sing when inside the bathroom but with extra effect (i do dance or act the song).
I also found myself thinking a lot and staying inside within minutes (least i guess is 10 minutes just standing there) before finally pour water on my head.
I used to think a lot too, like I would daydream a lot or think about all the things I have to do and next thing I knew time had gone by really fast. I think I have not done that like in 5 years, now I just take a shower as fast as I can before my kids think of something else they can make a mess of LOL.