It looks like Google is getting tired of the emails- "I accidentally clicked my own ad. Please don't ban me". Besides, they already knew you clicked an ad on your website. I admit that I even sent them an email a few years back. Now I just block the ads via the host file.
Here is the post on Inside Adsense.
As most of you know, our program policies state that publishers are not permitted to click on their own ads for any reason. For this reason, we've received many emails from publishers letting us know that they've accidentally clicked on their own ads. If you're one of these publishers, we truly appreciate the efforts you've made to monitor your account and keep it in good standing. However, we do understand that an accidental click may occur from time to time, so there's no need to contact us each instance this occurs.Because we closely monitor all account activity using engineering systems and thorough human analysis, chances are we've already detected your clicks on your ads and discounted them. While these clicks still show in your reports, we filter out their associated earnings so that advertisers aren't charged. However, please keep in mind that we don't ignore the clicks completely; if it appears to us that a publisher has been clicking on his own ads to inflate his earnings or an advertiser's costs, we may disable the account to protect our advertisers' interests.If you've been clicking your ads out of interest or to see who was advertising on your site, we strongly recommend using the AdSense preview tool as an alternative. This tool will allow you to check the destination of ads on your page without the risk of generating invalid clicks. You can also find more ways to view the URLs of your Google ads by visiting our Help Center.Discuss this postThis marks the last post of our ‘Policy Thursdays’ series – we hope you've found the information from the last few weeks useful. Thanks
Posted by Mike Deeringer - AdSense Publisher Support