A replacement for "you snooze, you lose." A phrased used when someone is taking their sweet ass time smoking a cigarette, and in doing so have missed an opportunity. This is generally the result of a single smoker idly wasting the time of several non-smokers, causing the non-smokers to abandon him.
The "croak" part refers to the fact that they're eventually going to die of lung cancer anyway.

When you eat dirt for the first time and leave your family to build a shack in the woods