9
is it possible to over object-orient your code
Yes
I think there are times when OO design can be taken to an extreme and even in very large projects make the code less readable and maintainable. For instance, there can be use in a footware base class, and child classes of sneaker, dress shoe, etc. But I have read/reviewed people's code where it seemed as though they were going to the extreme of creating classes beneath that for NikeSneakers and ReebokSneakers. Certainly there are differences between the two, but to have readable, maintainable code, I believe its important, at times, to expand a class to adapt to differences rather than creating new child classes to handle the differences.
I think anything can be "overdone". This is true with nearly every best practice I can think of. I've seen inheritance chains so complex, the code was virtually unmanageable.