Reg Gutteridge was interviewing Sonny Liston in the 60's and Liston was being all truculent and intimidating. He went over to the doorway, put his shoulders in it and shrugged the whole frame out. He walked back to his seat and said 'I bet you can't do that, little man'.

Reg got out a penknife, cooly opened the blade, then rammed it an inch deep into his leg without flinching. Unblinking, he looked over at a wide eyed Sonny, and said 'I bet you can't do that'. Liston exited the interview, suitably abashed.

What he didn't know was that Reg had a wooden leg, suffered during the Normandy invasions.

I saw that on an old documentary about Reg, and the best thing was that they actually televised that interview at the time!!! Priceless