One of the memories I have of watching the old man thermalling with his fully balsa Flamingo had to be mid seventies sometime. He bungy launched just like any other day at the old MADMAC Monarto field, as I watched what would have been a flight any thermaller would have been happy with. Over an hour of dropping in and out of lift, up and down the field, going out of sight several times (to me anyway). He finally lost lift enough to be on the final leg of this flight, as I watched him come in over the old cemetery, just over fence height the wings gave a tell tale flick and the glider jumped up 8-10ft (Flamingo was very light) or so and around he went only to circle out of sight again . I thought this is awesome, I sat and watched basically the same thing again, up and down the field, in and out of sight for about the same duration.
He finally brought it in (this time sick of it I think, just wanted a break and stretch the legs) but you guessed it, exactly the same spot, height, everything, De-ja-vu, up he goes again, this time it was shorter lived but all up it was a full arvo of 1 flight (not sure how the old Ni-Cads kept up). That afternoon was what hooked me to gliders and still love them to this day, some 40yrs later....