I think maths is rarely taught well. Those who are good at it just 'see' how things work, and don't/can't break them down sufficiently for those who don't. When I was doing the first year of my aborted pyschology degree, for some reason, I re-taught myself how to do simultaneous (I wouldn't have needed this for stats, would I?) and understood how they worked for the first time. it was quite revelatory. At school we were just shown how to do them.
I have always thought of myself as bad at maths. I just didn't really understand it, I think. Inspite of this, I suppose, I was made to take maths o'level a year early, got a B and was then made to do A/O in the fifth form. But after getting about 33% in my mocks, was allowed to drop it.
“In the midst of winter, I found there was, within me, an invincible summer." Albert Camus