think long and hard(redirected from one thought long and hard)
think long and hard
To consider something very carefully and thoroughly. You had better think long and hard before you say your next words, because you are on thin ice, mister. I thought long and hard about what colleges I want to apply to—it wasn't just a rash decision.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.