The more I learn about the world, the more I realise I have yet to learn. I came across this today, and the owner's comments immediately impressed upon me as my thought of the day.
The tattoo is an illustration of the Gestalt Law of Closure, and reminds it's owner that you should:
"stay humble, because you never know how much of the world you're making up as you go along"
I think a tattoo of an incomplete triangle is a radical way of remembering your maxims, but it certainly does help give the quote some authority.