Habits

The chains of habit are too weak to be felt until they are too strong to be broken.
- Samuel Johnson

Why are habits so hard to break?

Well, if you take a good look at the word, you will realise that :

If you take away "h", you still have "a bit" of it.
If you take away "a", you still keeping "bit" of it.
If you remove the "b", you still have "it".