What about when a product changes names, between your logins?
Take protonmail - they started to use “proton.me” instead of “protonmail.com” more and more often. If your f(x) was f(“protonmail”) originally but after being away six months you try in the middle of the night while hungover and driving in snow f(“proton”) won’t get the same result?
Take protonmail - they started to use “proton.me” instead of “protonmail.com” more and more often. If your f(x) was f(“protonmail”) originally but after being away six months you try in the middle of the night while hungover and driving in snow f(“proton”) won’t get the same result?