When I was learning to ride a bike as a child one of the most difficult things to learn was to remember to use the brakes. I recall forgetting how to stop the bike and use the brakes. I crashed a couple times until I started to get it.

I think that many times in life we don't know when to stop as well. If we don't know how to stop we will suffer the consequences in various ways. For instance, if we do not know how to say "no" to others we will burn out or become resentful. We may even develop more stress and health problems.