Nobody means to settle for mediocrity, but it happens. It happens unless you think about everything you do, and make every choice the best one you know how to make.
If you limit your choices only to what is doable; or permissible; or acceptable; or reasonable, you disconnect yourself from greatness, and all that’s left is second-rate. Ordinary. Indifferent. Pedestrian. Vanilla. So-so. Run-of-the-mill. Uninspired. Bog-standard. No great shakes. Lame. Mediocre.
As the saying goes, “Beware the lollipop of mediocrity. Lick it once and you’ll suck forever”.