When You Have Forgotten Your Gmail Password…
Change your Gmail password frequently, they said; and so you did.
Now, of course, you remember the password you had last week, and even last month's. But the current Gmail password? Who knows?
…Gmail Still Knows It
Gmail knows. It will not, though, tell you right away, of course.
Going through a validation process, you can set a new Gmail password—say, last week's—, however, and regain access to your Google account.
Recover a Forgotten Gmail Password
To reset your forgotten Gmail password and recover access to your account:
Make sure you either
have a secondary email address specified for your Gmail account or
have not logged into your Gmail account for 5 days.
Click Forgot password? on Gmail's log-in page.
If prompted, type your full Gmail email address over Enter your email on the Account support page.
Gmail will now ask a number of questions to try to establish you as the owner of the account. For each question:
Enter your answer as well as you can and click Next or
click Try a different question if you cannot answer or do not have access to the resource—a secondary email address, say, or a phone number.