This document proves that the meme is false and that Apple did not attempt to protect 'rounded corners'.

Apple asserted a design patent that protects the overall appearance of the iPhone - the 'trade dress'. Rounded corners are one of many attributes that describe the appearance of the iPhone. If you copy enough attributes - as the court ruled that Samsung did, you have copied the appearance.

Taking a single element out of context is a lie that Samsung originated, designed to give the appearance that Apple attempted to protect a ridiculously broad concept which the documents show that they did not do.