Singing Inside My Head

Sometimes when I go about my day doing things, chores, and going places (unless I'm at home by myself) I sing to myself, in my head.

Many times I make up a little tune, not randomly, but sort of out of nowhere. Sometimes I come up with little lyrics that go with my mini-tune.

Last week I was singing:

I like to hide inside myself
where no one else can see
it's very comforting

I don't think I was sad or depressed, that's just what I got.