Not everyone has had the same experiences, interests, or life/work opportunities in the same way, and this person seems genuinely interested in learning more. It's something to be encouraged.
Consider how would you respond if someone made a remark like this:
> Honestly, I'm always blown away by accounts [of] "so I just welded the pipes" dropped casually like this. I'm a plumber and have been for over five years, but wouldn't even know where to _begin_ with something like that.
Software has a huge surface area these days. That a trained software engineer isn't aware that HIDs and input subsystems are often highly hackable from userspace is no surprise to me.
They may also have been leaning into a compliment of OP in a self deprecating way.
shrug
C'mon. Don't shrug me now after going all proverbial pointy finger at me for expecting an "Engineer" to know the basics.