Who dares meddle with me?

Driving home this afternoon I saw in front of me a modest-sized white 4x4 with the classiest back-windscreen motto I've ever seen: Nemo me impune lacessit. It rang a faint and distant bell but I couldn't place it, and I've never studied Latin, so I sat there in the traffic trying to nut it out. Nemo means nobody, of course, and me is obvious, and it's a fair old bet that impune has something to do with punishment or the lack of punishment, but lacessit had me stumped. What could it all mean? 'Can't blame me for trying'? 'No jury would ever convict me'?

Five minutes later I pull into the driveway, leap out of the car, run into the house and google it before I forget it. Hooray for Wikipedia:

Nemo me impune lacessit is the Latin motto of the Order of the Thistle and of three Scottish regiments of the British Army. The motto also appears, in conjunction with the collar of the Order of the Thistle, in later versions of the Royal coat of arms of the Kingdom of Scotland and subsequently in the version of the Royal coat of arms of the United Kingdom used in Scotland. It is often translated as No one attacks me with impunity, or rendered in Scots as Wha daur meddle wi' me? ("Cha togar m'feargh gun dioladh" in Scottish Gaelic.)

Duh. Given that I'd just spent the afternoon with my father, you'd think Wha daur meddle wi' me would have been the very first thing I'd thought of.

It occurs to me later that it's really just the high-class version of that image you often see on the back of the car in front of you: Yosemite Sam twirling his six-guns and snarling 'Back off.' I love Loony Tunes, but I think I like the Latin even better.