I hate it when people say "it's not rocket science" when they think something isn't that hard. As if rocket science is so hard.
What the hell is rocket science anyway? I'm sure the people who do the thing that we think rocket scientists do call themselves something else. The point is, who really knows how hard rocket science is? Someone told me once that quantum physics is much harder, so maybe people should say, "This isn't quantum physics" and they wouldn't sound as dumb then either.
One of the surgeons I worked with used to say to me, "This is just vascular surgery, it's not rocket science." Well, let me tell you, I don't think a "rocket scientist" could walk in and do an aortic aneurysm repair just like that.