So when I send someone an email what address does he see? IIRC he sees meshugener.crazy@gmail.com if Google don't recognize, why does he see it? And lets say I sign in as meshugenercrazy, would he see it without the ..?
When it said "Gmail doesn't recognize periods" that means they don't distinguish it as a separate email address (as yahoo and others DO) and will deliver your mail anyway. The mail will arrive showing periods. In other words they notice and recognize the periods, but send the email to you anyway.
If you login as meshugenercrazy@gmail.com, the recipient will see the sender as meshugener.crazy@gmail.com as that is the only actual email address that you 'own'. For the future though, when giving out your email address, if it's easier to just tell it to people without the period go ahead and do that.