I know at least one pilot who, after a break of more than thirty years, flew a physically unaided circuit from take off to touchdown with no difficulty whatsoever.
That probably depends how much flying the pilot originally did and what sort of flying. I'd imagine someone who had hundreds of hours flying, lets say crop sprayers, could fly a very competent circuit in a basic trainer after a thirty year break. However, (unless a totally natural pilot) an ex student pilot with 27 hours would probably struggle after ten, let alone thirty.
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