On top of that, I think pixel perfect means that you'll notice if somethings even slightly incorrectly positioned.
Doing this job you get quite good actually, at estimating how many pixels an element has to be pushed up or down. In fact, I normally make that a game. Try to guess it.
Bad advice. Pixel Perfect means attention to detail, taking pride in a final result, being satisfied and feeling validated when you ship something.
Please, please continue to strive to make things you are proud of.