My mother-in-law was a kindergarten teacher many many years ago and she said it was typical to have to teach 5-6 year-olds the names of colors, shapes, and to identify letters. Then Sesame Street became widely available and the next generation of kids already knew everything they would normally teach.
Fascinating, I wouldn’t have expected that. I’m sure it depends on the family, too—my parents read with me from a young age, and I liked it, so I learned quickly.
In retrospect, 3 was a big year for me, haha. I remember going from not being able to read, to my parents finding out that I could read on my own (when they discovered me reading aloud the opening of Legend of Zelda for the NES) to reading proficiently by myself (thanks, Dr. Seuss!)
And at 4, I remember being very surprised when I went to kindergarten, and some of the kids made me read things for them because they couldn’t yet. I thought they must have been joking or making fun of me at first, but it turns out my parents are just great.
My daughter was reading at ~18 months. Or something like reading. You be the judge: My wife took 3x5 cards and wrote words like "BUCKET" on them and put the card next to the bucket in the kitchen. All over the house on things. Then she'd go around with her and point out "Look at the bucket! That card says bucket. Look at the chair! That card says chair." Etc. Then she'd gather up the cards and put them on the floor face up in a grid and say "Now go find me bucket!" And she would find the card. Soon after that she was pronouncing words on billboards on her own. From there she started to pick out and read books from the library. It was awesome but of course it relied heavily on my wife's patience every day to do this.
It's not just the parents. Some kids just don't take to it. My wife and I are both voracious readers, we read to our kids every day, and our 7-year-old is just not that into reading yet. On the other hand, her 4-year-old sister is picking it up great, and is only a few steps behind her sister. Each kid is different, and engaged parents are helpful, but necessarily everything.
Indeed, our 10 year old didn't start reading independently until she was almost 9, but now goes through a book a week. Our 4 year old and 6 year old are both at the point where they can read common words, and sound out simple phonetically spelled words (and we neglected reading enough to our 4 year old because we had 3 older kids we were dealing with), so the difference innate ability and interest have is huge.
Memory is such a strange thing. I don’t remember many things from that time, but what I do is as if it happened yesterday.
I can feel the crooked wooden floorboards under my bony pajama-clad bottom, and the NES controller in my hands with its creaky plastic buttons, and the warmth of the summer afternoon sun, and the vibration of my boy soprano voice reading the text on the screen. I can smell the static of the Sharp CRT television, and my dad’s warm chamois shirt with (I now realise) maybe just a hint of weed on it. And I can hear him standing above me saying “You can read?”
This kind of thing is what makes me suspicious when I hear education experts say that N is too young to teach kids X. It's fine for each jurisdiction to have its own ideas about when to introduce particular topics, but they probably have very little info about how well things would have worked at a different rate or in a different order.
This all goes n-tupley when we consider any individual kid in. In that case you should just see what the kid can do and wants to do for yourself and not bother with what teachers think they are unready for.