It used to be that my age and waist size were the same size. Unfortunately, they still are.

This is a self-deprecating joke about aging and weight gain. The speaker recalls a time when their age (in years) and waist measurement (in inches) happened to match—an amusing coincidence that implies they were relatively slim when younger. The punchline reverses the expected trajectory: rather than the numbers diverging as the waistline grows, they “still are” the same, suggesting the waist size has increased in step with age. The humor rests on numerical symmetry and the cultural anxiety around middle-age spread, using wit to soften embarrassment and invite recognition from others who feel similarly outpaced by time and metabolism.