Heard the same, about 50% not doing their first biannual. A friend with a flight school told me that of his students about 1/3 never set foot in a GA plane again after doing their license. I can only speak for me, but the confidence to really be able to be a pilot took about 100h after license. So, if you really want to continue flying, get a cheap plane, or share, or marry rich & old, or just hang out the bushes with hangar flying until a good friend let you fly his plane.