This is a short riddle which has a short answer.
I look like I have no memory,
but I am fine,
but turn me around
and I may knock you down.
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Sign up to join this communityI think the answer is
OK
I look like I have no memory
OK looks like 0K (zero kilobytes)
but I am fine,
OK is synonymous with fine.
but turn me around and I may knock you down.
OK backwards is KO (an acronym for knock out)