The answers you entered here trying to retrieve your account are not the answers to the security questions that you could have used from Google.
You would have done these things when you first created your account: add a mobile phone number, add a second recovery email, and set up two-factor authentication.
That two-factor authentication will give you the option to generate up to 10 one-time recovery codes you can then use to access your account.
If you didn't do these things and you have a free account, your only alternative is to create a new account.
People forget their passwords all the time, and Google has made it really easy to get access again.
Of course, if you changed your phone number and email address back in 2011 and those numbers and addresses are no longer good, then your account is permanently locked.
So, what happens when everything fails?
Here is a portion of the support thread
The only form of account recovery Google offers is with the creation of Google Accounts; accounts cannot be recovered in this forum or by Google itself.
Provided you are here because you posted because account recovery doesn't seem to work, being a bit more specific and utilizing a known computer/IP will aid your question greatly. You should also refer to the following:
Account Recovery - Google couldn't confirm that you own or control this account.
- Google Accounts Community - Provides a very general view of the procedure, giving you a heads-up early on (not all accounts are recoverable).
Gmail Account Recovery - Very detailed step-by-step on recovery of an account, with an explanation of almost everything you could look for including when the account was originally opened.
Sadly, Google won't offer you the method mentioned if you can't make use of it to prove your account ownership.