She actually had already started learning some reading at 4 when she was in preschool. It was mostly just sounding out letters but at that point kids can start to sound out simple words too. Preschool is elective though so plenty of kids won’t start that young.
https://en.wikipedia.org/wiki/The_Letter_People
…and I am fairly sure they had us reading short stories in first grade. (But only fairly certain; I could read short stories halfway through kindergarten, so that could be coloring my recollection.)
turning 25 this week…in base-16.
Motivation is one thing -- necessity is another. If you need it (not just want; literally need it for some reason), you'll have a pretty strong motivation to acquire it. (Or give up. But that's where parental guidance comes in.)