Even though I previously deleted the Firefox account associated with my usual e-mail address, Firefox appears to remember this account. However, it does NOT remember the password associated with this account. If I want to reset the password, I am told via Firefox message that this entails possible loss of personal data, incl. bookmarks, which defeats the purpose of creating an account in the first place. So I can neither re-create nor log in to this zombie account but have to use a different e-mail address in order to use Firefox account functionality. Getting help in this situation without a working Firefox account is also next to impossible (without a Twitter account, at least), as I needed to get an account even to access the page from which I am writing this. Firefox browser feedback is also disabled, Firefox Facebook is paused. If the above description is correct, then I guess the only help is a reworking of the Delete Account functionality. NOTES: * This is not a case of forgotten password (I wrote it down on paper at the time) or wrongly-typed password (I copied and pasted the password string from Notepad when previous login attempts had been unsuccessful.) * The deletion of the previous account took place on 2019-01-08 and included confirmation "Account deleted successfully". * When I created a new account for a different e-mail address today, I was informed by Firefox that a Firefox account had previously been created from the same machine for a different e-mail address. So, not only does Firefox remember the e-mail address of an allegedly successfully deleted account but also the identity of the machine associated with that account.