Brynna, our cat, is now fifteen and a half years old. She was born the runt of the litter, and grumpy about it -- she came out yowling. She was never very bright. Always scrawny, and almost always grumpy her whole life.
Somehow, though, even at this advanced age, even though she's having some systems fail (balancing kidney and thyroid medications, giving her subcutaneous fluid once a week, trying to get her to put on weight in vain), and even though she's wearing a collar with ten bells on it, she still catches mice. Tried to bring in a particularly juicy one today.
You've got to give the girl credit.