Habits from childhood

Have you ever noticed that we continue to do things that helped to calm us when young. I can remember back as far as I can that I have always twirled my hair when I start to get stressed. No thinking involved it just happens. My brother rubs his bottom lip with his finger. My youngest daughter twirls her hands together. I always ask her are you okay when I see her getting this way. Usually means she is excited or nervous, upset. We all have things we do without even realizing we are. What do you do?