As your key phrase is known only to you, my1login is unable to remind you of it.
The way in which my1login works provides redundancy should you forget your key and have to reset it. The redundancy differs depending on your user type.
If you're an end-user, resetting your key phrase will enable you recover all of the Logins that were saved as at the last time your admin logged in. You will lose the Username, Password and Secure Notes data for any Logins which were added after your Admin last logged into their account.
If you're an admin, resetting your key will enable you to recover any Logins which are shared amongst Users, but you will lose any Logins that have not been shared with others. If there are multiple admins, then all Logins (as at the last time another admin logged in) will be recovered after key phrase reset.