No one does, that's why we write unit tests. You'll eventually not remember you own code, and you can basically ensure the next guy to come along won't fully u

No one does, that's why we write unit tests. You'll eventually not remember you own code, and you can basically ensure the next guy to come along won't fully understand your code either. If you have good coverage, its like having a safety net to fall on allowing you to take large leaps.