I too could read and write well by the age of about four. I seemed to have more or less taught myself. My mother took me to meet the Headmistress of the 'Infant' school, which normally accepted pupils from the age of five. She heard me read, saw me write, and I did some 'sums'(bit of a performing poodle, but I loved it!)
I was allowed to start school with others a year older.
My wonderful teachers always found material suitable for my ability,and 'stretched' me. After a few weeks, I was moved up to join a class two years older than me.
I'm relating this to show how wonderful all my teachers were in accommodating my weird abilities.
Junior school was also excellent.
One thing that hasn't been mentioned yet is discipline. All teachers in those days were strict and had firm control of a class. Most important.
Some of my colleagues when I became a teacher found class-control difficult/impossible. This is a major fault in a teacher.
From various comedies on TV I remember:-
"It's your time you're wasting."
"You absolute CLOT!"
"I have eyes in the back of my head." (when writing on the blackboard)
"It looks as if a fly fell in the inkwell and walked across your exercise book."