[ludicrousdispla]

I think mistake is an overused word, and a choice that qualifies as a mistake in the future may not be judged as a mistake now.

Simply put... we make choices based on the information we have now. And our future judgment of our choices should account for the information we had back then, most of which has probably been forgotten.

But to answer your question, we shouldn't regret our mistakes but it is very good to remember them.