This–and the entire framing of the discussion–assumes that this is binary. You either 100% succeed at something, or 100% fail at it.

What I’ve found is that things usually aren’t that cut and dried. Most tasks are broken down into multiple subtasks, each one of which you can succeed or fail at. And for each there’s a spectrum of better and worse outcomes, methods, and other aspects. Which means that you may succeed at something, but still may be able to identify areas where you can improve.

For example, let’s say you deliver a project on time and under budget. Success! However, you also realize that if you’d reached out to Legal two weeks earlier you wouldn’t have had to scramble to get the paperwork in on time, and if you’d used this vender instead of that one the product would have been better in ways that may matter to your next client, and your own records could be improved so you don’t spend so long looking for emails in the future. None of these were in themselves failures, and the project did get done on time and under budget! But all of these are areas where you can improve in the future.

The quality of an employee has little to do with whether they’ve failed in the past. It’s the ability and willingness to constantly strive for improvement in areas that you care about. If they’re doing that they can turn a failure into a learning experience. But they can also turn a victory into a learning experience just as easily.

If you succeed at something, you’ve learned nothing, because you already knew what you were doing. Only failure teaches us new things.