There are three of us that started about the same time, the major diff in learning was from my experience, is that 15 hours will get you going up wind and starting to get quite confident , we kite all year round with dodgy winter gusty conditions

which hones the skills significantly when summer comes back around.

by the end of summer if you can out 3 times per week the following will happen

A) your skills for self launching, self rescue, self landing will have improved significantly

B) you will be totally addicted to the rush !!!! of kitesurfing
C) You will be buying a newer faster responding kite to meet your improved wave skills

the frustration goes after you land your first jump or snap one off the lip