Ref all the previous replies, it's all about practice. One day, it will just click!
CODECO is pretty straight forward, once you get your head round it....
I was learning shares Continental shares system, last year, and that was a two-week residential course in LGW....Now that WAS involved ! And that took a fair bit of shadowing once we were back on base.....if you ever get chance to work with Continental/United, then take it, cos if you can master their SHARES system, then you can master anything !
GOOD LUCK !
LB