Today's Word of the Day means...
"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 Amer.Eng.
To be active and high-spirited; act brashly and confidently: The manufacturer was just feeling his oats, having accomplished his happy intention
[1831+; fr the vigor of a just-fed horse]