Ever been asked if you were old enough to do your job?

This just happened. Happens every so often.

" How long you been working here"?
..."and [i]you're[/i] a social worker"?

Me: um, yes.

Him: " Oh ok, it's cause you don't look old enough to be working here"

I said " you don't think I can do my job? I got this..."💃

He was friendly though, that's why I gave that response