New Year’s Eve for us diehard older golfers sits a little differently than for “normal” people.
More context for this joke if you are interested.
New Year’s Eve usually means staying up late, celebrating, and starting the year tired. Golfers tend to think about it differently. An early tee time changes the math. Midnight stops being the main event and sleep becomes the priority.
The joke is the contrast: one group planning to close out the night, the other already planning the first round of the year. Anyone who plays regularly recognizes that tradeoff.