You don't have to be a 'rocket scientist' [=you don't have to be unusually smart] to understand the instructions.
Sales 'rocketed' from 1,000 units last week to 5,000 units this week.
The job is challenging, but it's not exactly 'rocket science'.
(..) grocery store. and the minute I turn on a fucking game she starts crying we never talk. See now go out, come back and talk to him. And it ain't a rocket science for Christ sake. Yeah, but I don't have a job, a car, or a girlfriend. Jesus, I should have blown his head off when I had a chance. (..)2008 Gran Torino