I came across this blog today via Yess BMX, this guy in Scotland has set himself a couple of bike related challenges…one of them being to compete in the BMX World Champs in Colombia in 2016, oh yeah and he wants to be World Champ!!! he has ridden trails etc but has never raced BMX before.
I reckon it is possible for him to get to the Champs, not so sure on the rainbow jersey though haha.
Good luck mate.
Have a read of his blog here and keep following for updates.