A garage door is one of the main entrances of a house, so it can reasonably be inferred that its door opener remote holds the same importance as your house key.
A house key and a door opener remote also have another thing in common: they are lost quite often. It can be lost due to several reasons like it could have been misplaced, it could have been stolen, or it could have dropped somewhere, or maybe you lent it to somebody, but he didn’t return it.