I saw this terrible ad in a terrible magazine and immediately thought 'that's never a Mark Twain quote'.
He never wrote like a terrible copywriter writing a brand values. In fact, people in general never wrote in that odd one word per sentence way in the old days. Did. They? And those words, feels too much like the Everyday Contemporary Luxury style of copywriting you see on housing developments these days. Never a Twain quote.
Turns out he might have written it as part of a much longer piece, but probably not.
" 'Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did. So throw off the bowlines, Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.'
This quote has been attributed to Mark Twain, but the attribution cannot be verified. The quote should not be regarded as authentic."