The truth is, your clients are satisfied with less than perfection. They want excellence, and they want the job done on time, but they don’t expect perfection.
So if you’re devoting big chunks of your time trying to reach for absolute perfection, you’re doing it at the expense of other projects, or new business prospecting. In general, the quest for perfection takes more time and effort than it’s worth. I suspect it’s not really attainable, anyway.
Get the job done, and done well. Then move on.