One of the first wrestlers I saw pull off the double dip wrestled U8 (placing 1st) in the morning and U10 (placing 2nd) in the second session. He has had an incredible high school career so far going 3rd, 1st and 1st at State. I wouldn't bet against him to win his 3rd this year.
I have also seen other wrestlers get extra matches in and wrestle a lot of tournaments (a whole heck of a lot of mat time) when they were young and have a lot of success. The sad part of this story is that they either didn't wrestle in high school or started but didn't finish. Burn out does happen, or maybe just life happens.