The entrance sign said 

                  “Admission - $20 

                   Seniors   - $10”

    But nowhere was there a definition of “Senior”.

    Since getting my Senior Citizen Beach Permit from the Town of Oyster Bay (undated but good for “Lifetime”), I have become aware of senior  discounts. Although you start getting offers to join AARP at 50, I've seen senior discounts offered at 60, 62 and 65. I have yet to identify the determining factor for the differences in the crucial age cut-off. Moreover, I've noticed that rarely are you “proofed” for a senior discount.

      We waited on line and approached the counter. It appeared that the woman was a "senior" in her own right.

      “So, what's a senior?” we asked. “If you have to ask, you're a senior!” was the gracious response.

      I think it's as good a benchmark as you can get.