I'd agree with the brushing thing. I thought my hair was wavy and big rather than curly when I was a teenager as I would brush it (and hence mostly wear it up as I didn't like the bushiness). I always thought I had really thick hair as there was so much volume. Turns out I don't!
It has only been the past two years I have really stopped trying to detangle whilst my hair is dry
get frustrated and basically rip through my hair with a brush
I now detangle in the shower with conditioner and running water - my hair condition is so much better.