I have created an email long years back in I guess year 2008 with ID say [email protected]
and some person has created a new email named hello.world@gmail.com and now I am getting his emails on my gmail account.

I googled and found that gmail system ignores [.] in email ids and all emails having . will land to one email.

so hello.world - h.elloworld - hell.oworld etc will go to helloworld

my main concern is since I am receiving other person email on my gmail ID can this go vice-versa too?
like if someone sends an email to me at helloworld , can the other person with ID hello.world see my emails too?

Wow... if confirmed, this would be one of the most MASSIVE bug I've ever heard on the net!
It seems really strange to me to see a so ordinary, trivial and "blasting" bug on world email service like gmail

It took me 10 seconds to find this:
https://support.google.com/mail/answer/7436150?hl=en