The statement was "<year>, when I was 3 or 4 years old". I took that to mean it was closer to four, which is not that weird of an age to be able to read. Or at least I thought so, until I looked it up. I guess it is pretty unusual.

Children who can’t read browse the Internet using visual cues (bookmark buttons, suggested sites, sometimes recent site autocomplete, etc.) All mouse or trackpad based. It’s obviously limited and from my observation, they have no idea they’re missing so much.

When I was 4 years old I was playing mac games on Mac OS 7 I think..