Many years ago at a secret ISTAR base in Lincolnshire, there was a joint exercise/briefing, and some members of the SAS and the SBS were to be found in the bar. They were in deep discussion about which unit was the "hardest" when one of the Sqn AEOs (who just happened to have an artificial leg) took out his dinghy knife and stabbed it into his leg (the plastic one) with the comment of "Hard - I'll show you hard". He then limped out. His comment afterwards... "I write off more legs that way.."