That's the attitude I am trying to avoid these days. When I look at something that I want to rewrite I now ask the following questions,

1. Do I have sufficient tests and testing to do this without breaking things?

2. Do I want to want to rewrite because I cant be bothered understanding it?

3. Is there going to be any gain now or in the near future by rewriting it?

4. Will I be able to rewrite it sometime in the future as part of another piece of work which actually delivers value?

Unless I come up with Yes, No, Yes, No I tend to leave it alone. There are other things of value I can do with my time.

EDIT - Formatting...