Explorers: Geographical boundaries or Human Limits?

IMG_4687.JPG, originally uploaded by www.alastairhumphreys.com.

Last night I spoke at the Arete Club at the very plush Oxford & Cambridge Club on Pall Mall. Thankfully YouTube taught me how to tie a bowtie in time. The discussion was titled "Explorers: Geographical boundaries or Human Limits?"
Unfortunately I came unstuck at the first word. Google Earth has removed the need for anyone to claim to be an 'Explorer'. I don't like calling myself an 'Adventurer'; it just sounds a bit daft and puerile. And 'Writer' gives the wrong impression: I write to ride, not the other way round.
But it was an interesting evening, and I was relieved to find that the very clever audience were still curious about the sore-bum suffered by cyclists, as well as fellow speaker Jake Meyer's concerns about peeing at -70C in Antarctica!