I am a new member of this community and seems there are many users who are looking for a way to recover Gmail account, forget passwords, lost recovery mobile no. and so on.
Just for sharing... "Precaution is better than cure"
So, it is recommended you to create Gmail email's backup first so that in case you can access your crucial emails...
--> If you add recovery mobile no... then add a backup recovery number also.
--> If you added recovery mobile no then.. generate a copy of backup code.. In this copy you will get 10 unused code to access your a/c.
If there is more suggestion for securing Gmail account then I love to hear from you.