How hard is it to learn to surf foil?

Firstly while anyone can try and everyone has the right too.
For the safety of both the learner and the other people in the water we believe learning to surf foil is, best suited to intermediate surfers, experienced water men and women and above. 
Having said that it is about the same as learning to ride a bike. ( a bike with one wheel and no brakes) No joke learning to surf foil is very similar as it has a lot to do with muscle memory. 
If you can a good way to help speed up the process is to tow behind a jet ski or boat (any size) and practice slowly rising up and touching back down. Ideal speed is between 10 and 15 miles per hour. 

Once you have done that or 


What size surf foil board should I get?