Le Baron wrote:I'll add... I knew an Iranian fellow here who lived more than half his life in the U.S. (after leaving Iran at age 18 in 1980) and he used to claim he'd 'forgotten how to speak Farsi'. All the time. 'Can't do it any longer...!' Then when we were renovating his house a woman came round from a company selling management software and he'd invited her in because she was also Iranian (and lovely) and by dint of some cupidinous miracle he was speaking Farsi with her.
I think this is where we need to make a distinction between "memory" and "recall".
Native speakers who go a long time without speaking their language do experience difficulties with recall -- they haven't forgotten the language, they find it harder to access it.
I imagine your Iranian friend's experience was that he couldn't choose to recall it consciously, but as you saw, he hasn't forgotten anything.
So yes, you're right, but there is a little more to it than "lose" vs "not lose".