Nothing, that is, except for having your account hacked.
Regardless, there are several ways to recover your Gmail or Google account.
Here's what you need to know.
Locked out of your Google account?
There may be times when you go to log in to Gmail, Google Docs, or any other Google site and can't seem to remember the email address or password you used when creating your account. Luckily, Google makes it easy to recover your account information.
However, you will need some information to recover your account, whether it's your email address, the date you created your account, or your phone number.
To recover your user name:
If you don't use your email address often or if you never wrote it down, you might one day find that you've forgotten it. Google makes it easy to recover your user name.
To recover your password:
If you know your user name but can't remember your password, you can reset your password to something else.
If you have a recovery email address, you will be sent a verification code to reset your password. If you don't, you will be asked to type an email address or phone number where you can receive a code.
Once you receive the code, type it and click Next.