It can happen fast. You can lose your email address even if you have had it for years, simply by forgetting the password and not having a backup email for recovery.
I encounter this all the time. Especially with those who have had the same account for years and possibly the same password. Email providers are requiring more security from their customers and that means changing a password frequently.
Forgetting a password is easy. So is making sure you have a way to get it reset if you forget it.
You can use a friend’s email, a spouse or other trusted person to be your backup for lost passwords. They won’t have your password, but the provider can send them a link so you can change it.