> If you forget it though then you can't reset your password anymore either.
If you struggle with memorizing your username/email, there's a near zero chance you're using a password manager, which also means there's a near zero chance you're using decent passwords for your logins, in my experience.
It happened more than once that I didn't store a login to the password manager correctly. Either mixed up something while editing, or forgot to save it at all, or accidentally deleted an entry, and only noticed years later (long after old backups were overwritten).
If you struggle with memorizing your username/email, there's a near zero chance you're using a password manager, which also means there's a near zero chance you're using decent passwords for your logins, in my experience.