(Strip Number 1192, Original Publication Date, 18 August 1987)
Panel 1: Since Jim doesn't realize that his grandson thinks forty is too old to live because he has a mother and father who scream non-stop about how their lives are all used up, Mike's asking him point blank what being old is like astonishes him.
Panel 2: He then tries to explain that sixty-five isn't old. His only as old as you feel speech has him state that he's still young (in comparison to the old lady who used to live next door) and in the prime of his intellectual life. Sixty-five is simply a number.
Panel 3: For some reason that's probably related to Lynn's belief that people age terribly, his belly bulges out.
Panel 4: This occasions bad wordplay about it being a ROUNDED figure.
Summary: You can't actually blame Mike for thinking the way he does what with parents who spend their time wailing about being too old to live when they're only THIRTY FIVE!!! years old.