Is it ok to know you made a mistake but not know exactly why you made the mistake?

I made a life altering mistake and may not be able to continue down the career path I have worked for years for (door is not shut, but will just be more difficult now). I can’t give too many details on the actual mistake, but I broke a rule and was given punishment from my institution. I know that what I did was a terrible mistake and not okay, but I honestly don’t know why I did what I did. I didn’t mean to cause any harm (I know not an excuse in the slightest) and kind of felt like I was on auto pilot. I am trying to be kind to myself and to learn from this mistake to make sure I never do it again, but I wonder if I would be missing the deeper meaning behind it if I can’t pinpoint exactly why I made the mistake. I also don’t know how to approach the question from potential future employers when they ask “why did you do it.” They will probably want a very concrete explanation to feel confident that this will never be an issue if I work for them, but I currently I don’t have a very concrete or relatable explanation. I have been more focused on the future and changing how I live my life so I don’t do it again.