Did you learn anything from your failed start up?

I'm curious to get the communities take on whether you learn more from start ups that have failed, than start ups that have succeeded.

Here is my thinking:

I've read many of the "keys to success" type of books, e.g. "Good to Great" or "The Art of the Start", but the information always seemed either inapplicable or flawed. Ultimately it seems very challenging to know why we have succeeded, but our brains are very capable of designing reasons in retrospect. It's my understanding there are a wealth of studies that support this theory. In "The Black Swan" Nassim Nicholas Taleb goes into some nice detail on the topic. Basically, we create narratives that make sense. "Our company was successful because of our culture" - that sounds good, but who knows if that really was the cause. The solution is not to look at all the companies that were successful to see if they also had a similar company culture, but to look at the companies that failed to see if they also shared that trait. If they did, then that trait is not THE key to success. But successful entrepreneurs(/people) are very prone to create a narrative cause to their success, and attribute that cause to actions - instead of chance.

Have you learned more from your failures or your successes. If you have had a failed start up, did you walk about stronger? Do you think you would have learned more had you been lucky and successful? Could it easily have gone either way, or was it doomed?

Thanks for your thoughts!