I guess I was pretty lucky with teachers though to be honest, beyond learning to read and write, I'm not convinced I learned anything much at elementary school. I can certainly remember quite precisely the point at which I grasped that there was something more to mathematics than puzzle solving (though I was damn good at that - I scored 100% on both the Common Entrance maths papers). It would have been in my first year in the Upper School (ie I'd just turned 13). I got my hands on a copy of Edwin Abbott's Flatland and I was hooked. I wonder how many budding mathematicians have been similarly snared by that slim but venerable volume.