The word ‘memory’ can be either a countable noun or an uncountable noun. When the word ‘memory’ is used in general, the uncountable noun should be used. However, I have a doubt here.
From how I perceive it, the word ‘people’ means persons in general, so the word ‘memory’ should take a general meaning, and it should read ‘People have short memory’.
I do not understand why the word ‘memories’, which is a countable noun, can be used to describe persons in general. Please enlighten me.
Given that usage, then the use of the word ‘p[eople’ becomes even more confusing, because in that particular sense (nation) the correct usage would be:
‘These peoples have a short memory.’
This is the exception to the rule of ‘people’ being plural and not needing a suffix to make it plural.