I spent my entire Army career in the Royal Corps of Signls, so wearing the dark blue beret and the badge of Jimmy Mercury. However, for around a week or so in Bosinia in the early 2000s, I wore the Tam O'Shanter, with the White Heckle, of the Royal Regiment of Scotland. Why I did that I won't/can't go into, but I did manage to follow the advice of their Regimental Sergeant Major who said to me the first day we went out of the camp, "Phil, just keep your mouth shut, you sound %&@! all like any of us and will stand out like a sore thumb." (okay, he didn't use the analogy of sore thumb)
