I very frequently go back to my own old answers and re-edit them, but they are mostly only minor edits:
- Fix typos
- Improve formatting
- Change wording if it's misleading
- Make them more up to date
Often I'll do this many, many times if an answer is popular and has existed for quite some time.
However, I have learned that if you do this enough times you lose the ownership of the answer and it becomes community wiki. The theory behind this is that people edit answers to bump them to the top of the questions list again and these people need to be penalized.
Here's an idea - instead of penalizing people for improving their answers too many times, why not allow them to improve their answer without it bumping the question, and therefore without counting towards the too-many-edits penalty?
A checkbox like "this is a minor edit" with some hover text explaining that it won't bump the question to the top might do the trick. I understand that previous requests to simply remove the bumping altogether have been turned down.