First email client was outlook express, than thunderbird, than gmail.

I tried mutt, i tried others.

I'm not syncing my mails anymore i just get an pop up from my webbrowser that a new email is here.

I also use different computers (home desktop, home laptop, work desktop) and prefer the same ui with the same settings on all pcs. The browser became in some way, my operating system for mails.

Is it that surprising? Webmail has existed for longer than most people have had email and it's not tied to a job or ISP like the previous most popular options were.

Most of the gmail users I know are a bit clueless and lacking in the technical domain and don't understand what an email client is because they've only ever used webmails. So I would not be surprised if they were unaware of pop and imap.