It is good to apologize if you walk into someone.
Joe is running late to work and has to stop at the store for an item on the way.
Joe wants to check out as fast as possible.
Joe bumps into someone as he hurries to the check out and apologizes quickly.
Joe rushes through the store bumping into someone and proceeds without saying anything.
The other customer shrugs it off as an accident and thinks nothing of it.
The other customers think Joe is quite rude.