Perhaps the habit came from being the youngest of a large family.

The habits of the area come to this museum.

Unlike his wind, the habit of talking to himself came back right away.

The old habits of teaching a group came back instantly.

Environment, daily habits and hereditary factors all come into play.

This was the first time the habit I'd developed as a youngster came in useful.

The habit of talking to himself when he was alone on his bike had come back in a hurry.

He knew it wasn't really necessary these days, but sometimes old habits came back to him.

This habit came from the years of running; you got ready to move again, first thing after you stopped.

That habit also comes in handy at home, since infections can happen anywhere.