The user has cats: what your site looks like just on the corners of the screen (or maybe even one or two corners) while random keys are being pressed by paws.
The classic "How does your site perform if your cat is standing on the F11 key" test
With the standard, classic result: "poorly".
Lately my 3 year old's favourite passtime is to come sit on my lap while I'm trying to work (or surfing HN or whatever) and ask, "Can I press this key?" (Shift? "Uh, ya, sure.") "Can I press this key?" (Ctrl? "Sure.") Some of them make you think though. (F2? What will that do in this context?)
It's not among my most productive times, but it's fun. :)
Your cat is talking at 3 years old? Very advanced!
I told my 2 and a half year old that the "S" key is the snake key, so now he always asks "can i press snake?". He's also found a second snake (the 5 key).
When he finds the '@', he's gonna be delighted!
I let my 3 year old play with my laptop at times, by giving her a full screen xterm running bash in a separate tab on my tiling window manager. She mostly likes to type the letters she knows (her initial, my initial, uncle's initial etc) but it's surprising how often she manages to Ctrl-R or Windows-Shift-3 or some other combo that makes things go haywire.
I hope she's not called Rebecca Mary-Rachel Ford ...
And has a cousin named Star.
Haha! Fortunately, her initials are not all in ASCII, so it's not gone wrong yet. But true, I should set her up with a user account that doesn't have write access on anything.
Install sl(1) and teach your 3 year old to type s l ENTER :-)
Boy, am I going to regret installing this in about an hour.
AWS failed this test hard for me a couple weeks ago. A cat walking across my keyboard terminated an EC2 instance. Lesson learned: no cats on the desk when logged into mission critical software :)