古英語のate、オート麦の穀物、野生のオート麦から。
That wilfull and vnruly age, which lacketh rypenes and discretion, and (as wee saye) hath not sowed all theyr wyeld Oates. [Thomas Newton, "Lemnie's Touchstone of complexions," 1576]Hence, to feel (one's) oats "be lively," 1831, originally American English.
Fred: I still want to sow some wild oats!
Lamont: At your age, you don't have no wild oats, you got shredded wheat.
["Sanford and Son"]