According to Google Support you can use the recovery link on this page: Recovering sign-in information
From here, you should try with all accounts you are associated with to see what accounts are linked. (Assuming you remember all email accounts used apart from the one you forgot). It is sort of hit and miss but it has worked for me on two separate occasions.
You should get an email similar to the following.
Your recovery address, phwd@gmail.com, is associated with:
xxxx@gmail.com
xxxx@gmail.com
xxxx@gmail.com
xxxx@gmail.com
xxxx@gmail.com
To sign in, visit the link below.
http://www.google.com/accounts/
If you've received this mail in error, it's likely that another user
entered your email address by mistake while trying to recall their
username. If you didn't initiate the request, you don't need to take
any further action and can safely disregard this email.
If clicking the link above does not work, copy and paste the URL in a
new browser window instead.
Thank you for using Google.
For questions or concerns regarding your account, please visit the
Google Accounts FAQ at http://www.google.com/support/accounts/.
This is a post-only mailing. Replies to this message are not
monitored or answered.
As seen above it works for multiple accounts. So any account that has phwd@gmail.com listed is brought up in the list.
Additionally you can search your email accounts for the following subject line
Your Gmail address has been created
This will bring up (if you didn't delete it), the confirmation email messages of all Gmail accounts you used the current account as a recovery point. Although, based on "used in ages" I am not sure how far back Google used to send out this message.
tl;dr: click continue at to reset my password from a device I recently used to sign in
and answer the not-very-secure questions presented to you, they will send you a mail.
long version
After reading this answer by icantchooseoneRising:
icantchooseoneRising Nov 2 with there being around 450 million gmail
users , there is no number to call if you use free gmail nor any
direct email or other type of tech support - its simply not possible
You can only reset your password by one of these methods:
Having email sent to a recovery email address that you have registered in your account
Having a code sent to the mobile number you have registered in your account
For some accounts, answering a security question.
filling in the recovery form
for 1 2 3 click here
select I forgot my password
for 4
Start here - www.google.com/accounts/recovery
Choose "I forgot my password"
Enter the account name that you are trying to recover
Solve the Captcha if one is offered to you
Choose "Verify your Identity"
Complete and submit the form
for more info See the following article about how to recover a lost or
compromised account: http://gmailaccountrecovery.blogspot.com/
I've decided to try and click continue on to reset my password from a device I recently used to sign in
, well, I've used my computer...
to my surprise it asked me to enter the last password you remember
then it asked to Enter an email address where we can contact you
- note that it didn't ask what is my 'recovery email address' (neither it should, based on my username they should know already), nor even my username...
After that it asked me again what was my last password, the date when the last tiem I could log in (today..), and the date when I registered my account (ages ago...).
I don't know what to think but it sent the recovery email to the address I've given.
I was able to recover my account.
On the first login, it tried to trick me again into giving my email address, but there was a "cancel" button...
Now I wonder if it didn't enter to this form the same address that is my recovery email address, would it still send the help email? Because then I think it is very insecure.
The reason why they don't allow me to log in with my password should be that someone else may be knowing my last password. So they can enter it too.
They ask for an other email address, not my username nor my recovery email address. If I could give any address here, then the remaining questions are the last time I could use my account, which is not very hard to guess if someone is an attacker; and when did I register. This one can be tricky, but really, there are not many combinations. With a little inspection, information and luck, one could make an educated guess.
So it seems what actually protects my account the strongest is my last password - the very thing that Google wants me to change. But until I change that, it seems that it may allow anyone with a random email address to take over my account, if [s]he can guess the time I've registered?!
Best Answer
"emergency account recovery key" was generated and sent to you during your registration via your email client