Humor: Why should I 'have a good one'?

Retail clerks, recovering accountants, and others who hold me in low esteem have begun to wish me "a good one." They say, 'ꀜHave a good one'ꀝ instead of 'ꀜHave a good day.'ꀝ

Perhaps they ceased wishing me a 'ꀜgood day'ꀝ to avoid my devastating rejoinders:

• Great idea. Why didn'ꀙt I think of it first?
• I'ꀙve already had mine this month.
• Not today, but Friday might work.
• Thanks, but I'ꀙm married.
• I have other plans.

I am befuddled by 'ꀜhave a good one.'ꀝ Exactly what are they suggesting: A good day? A good quadruple bypass? A good soup and salad lunch? A good religious epiphany? A good tea party? A good bowel movement? A good Zen koan? The possibilities are endless.

I could reply politely with, 'ꀜHave a good one yourself.'ꀝ But what if the recovering accountant meant, 'ꀜHave a good attack of shingles?'ꀝ I would not wish shingles on anyone other than a Yankee fan.

I am currently testing five responses to 'ꀜhave a good one'ꀝ:

• The probing: 'ꀜOne What?'ꀝ
• The confrontational: 'ꀜAnd then what?'ꀝ
• The non-committal: 'ꀜI will consider it.'ꀝ
• The avaricious: 'ꀜWhat not a good two, or even a good eight?'ꀝ
• The retributive: 'ꀜThe same to you if you'ꀙre a Yankee fan.'ꀝ

Thus far, the above rejoinders have elicited remarkably similar responses — 'ꀜasshole,'ꀝ 'ꀜjerk,'ꀝ and 'ꀜI discern that you are not a native Seattleite.'ꀝ

Results of my research will be published in Tenure: The Journal of Academic Academics.