This is actually like “my first almost-bug,” in “my first program” which was a re-telling of the Corn/Fox/Chicken puzzle.   I had written statements (in BASIC) like this one:

IF F AND C AND L = 1 THEN 80

Although the program technically “worked” as written, my mentor at the time pointed out that it was not written the right way.   The computer interpreted the statement this way:

IF (F) AND (C) AND (L = 1) THEN 80

... and it “worked” because a nonzero integer, in that particular (data-typeless...) BASIC dialect, was interpreted as “truth.”   But it did not express my thoughts at the time:

IF (F = 1) AND (C = 1) AND (L = 1) THEN 80