The skill set needed to fly gliders is slightly different to that required to fly power.
Once you have gone solo and have moved to single seaters and have begun to cut the apron strings, so to speak, the constant monitoring does not stop.
As an instructor, cross country pilot, advanced aerobatic instructor I am still regularly assessed and have to fly with CFI's, regional examioners etc on a fairly regular basis.
I have to fly a certain number of instructional flights per year and a certain number of instructional hours plus a certain number of solo launches and solo hours per year to retain my instructor rating.
To just be able to get in a glider and fly I have to have completed flights within the previous month. If not, I'm straight into a two seater with the CFI for currency checks at least one of which will be launch emergencies.
There is a very strong ethos of safety and constant monitoring for all pilots.
Though we don't legally have to have a license there are various qualifications that a pilot goes through from ab initio to early solo to building more experience.
The safety culture is the strongest I have come across in aviation and the training standards are very high.
The various stages in development are too long to list but from more info you might find a visit to the BGA website useful.
http://www.gliding.co.uk/