This small paperback took me several years to read. And at the end of it, not only had I grasped a number of mathematical concepts that had eluded me thus far - I also understood why they had eluded me.
Skemp builds from the ground up: what is a number? Why does counting work? Is adding natural numbers the same as adding rationals? He does not go into imaginary numbers beyond mentioning them briefly. The aim of the book is not to teach mathematics, but to explore the psychology of why so many of us give up on mathematics.
You can get only so far by rote learning (pretty far if you're bright). But you are building an edifice on weak foundations. Until one day you are confrointed with what is a concept too many. Another trick you are forced to learn, without real understanding (or explanation) of why it should work.
Such rote drilling is an insult to the intelligence - in both senses. And is not surprising learners rebel in a variety of ways.
Read this book and realise what has been stolen from you by imcomprehending teaching (incomprehending both of mathematics and the psychology of learning). And rage.
Then see it happen to your primary school kids and order a gift copy for their Headmaster...