We all make mistakes, it's common and we all learn from them
and also to mention that it's understanding the system also, if you don't understand the system then of course you would not know till you find out about it when it's too late.
When I first had AdSense going back 15 years ago, I was running a site I had someone other staff member who has sent be money to help me out with the costing of the server and he decided to click on ads ;P Yet he spent most of all the days and weeks clocking ads to get earnings and crazy part that in the stats we had over $300 USD worth of clicks ads
I had an email at the end of the month stating that they has to close down the account with that stats and it was a big problem, anyway I was able to resolve it and stop the MADNESS and the account never got closed down