I started off thinking aircraft must be a bit complicated, then I found out the wings and aerofils were complicated. Then the engines and cooling systems were complicated. It turns out even the bloody propeller is so complicated I cant really get my head around it, I must be getting more and more stupid. Or maybe the various ins and outs of a propeller, having to transmit 2,000BHP from zero to 500 MPH at all altitudes and up to 9 G is quite complicated, requiring more than 2 minutes thought to figure out?