The lock and key theory can finally be disproved. The lock and key theory states that "A key that opens many locks is a
master key, yet a lock that can be opened by many keys is a useless lock"
The counter theory, the pencil and sharpener theory states that "a pencil that is sharpened by a lot of sharpeners becomes a useless stub/pencil while a sharpener that sharpens a lot of pencils is a good
pencil sharpener" This theory is rarely favoured by males... for some reason.
Are you curious to know how this proof was derived? if YES, Click on Alt + F4 (on windows) and ⌘ + Shift + W (on a mac)