(one) is old enough to know better(redirected from one was old enough to know better)
(one) is old enough to know better
One should have enough experience and maturity by now to have the sound judgment not to do something. Tommy, why on earth did you draw on the walls with these markers? You're nearly 11, you're old enough to know better! The offer they were making was certainly tempting, but I was old enough to know better than to invest in something that sounded too good to be true.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
old enough to know better
Mature enough to have good judgment. This phrase, sometimes completed with but young enough to learn, dates from the nineteenth century. Oscar Wilde played with it in Lady Windermere’s Fan (1892): “My experience is that as soon as people are old enough to know better, they don’t know anything at all.”
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer