Pre-Patio work, we had what seemed like an acre of invasive, spreading mint and fennel. A little mint is very convenient when making drinks like a mojito, or you've run out of gum, but a lot of mint is a total pain in the butt.
I was making a recipe recently and went outside to get some mint. Franca and I hunted high, and we hunted low. This hunt essentially consisted of me walking around tasting a bunch of lemon balm. (Which looks like mint, but tastes like... you guessed it: lemon.)