If that was so the Aristrocrats would be having a hard time of it and as most of the law lords lean towards the gentry I can't see that being the law!!
In Scotland, the Prescription and Limitation (Scotland) Act 1977, provides that if you posess a property openly, peaceably, and without judicial interruption, for a period of 10 years from the date possession commenced, you can register a conveyance in your own favour.
So your friend, in the context of Scotland, is talking merde.