It is common for people to have various passwords for many different accounts, so it is quite common for somebody to forget which password they use. The providers of the accounts realise this and offer a fairly simple strategy for retrieving forgotten passwords and to grant access to the account.
If you have forgotten your Gmail password then follow these steps:
1. Head to www.google.com/mail
2. Click on the button that says 'Can't access your account?'
3. You will be asked to put in your email address or Gmail ID
4. Next you will be asked to reset your password. Think long and hard about this - you don't want to forget this one!
5. You will be emailed an activation code to the alternate email address you used when first registering
6. This needs to clicked to show you are indeed the owner of the Gmail account, this should then reset your password and you can login with the new one you specified