Thank You and Sorry

How many times does a person use these words daily?

I know it differs with every person. Some people feel its not needed to say these words unless its something big. But then why should you take the word SORRY as something so Big and never use it? Why not think that the Sorry can make both the person feel better and Thank you can make you feel happier?

I end up using both these words with every person around. I use them right from the stranger in phone to my friend and sister. No one has an exemption. Somehow it makes me feel good when I convey my sorry / thank you and hope it has the same effect on the other person :)