You do reveal something about yourself, however, if you leave a comment. The comment system requires you to leave an email address. It does not require you to leave a valid email address, but it requires you to fill something in the form, which will tell Dr. Boli either what your email address is or how imaginative you are. Commenting will also reveal your IP address, so that your comment can go straight through if you have already made a published comment. Otherwise, the only thing Dr. Boli has ever done with IP addresses was to ban some of them when they sent him a spam comment every ten minutes.
When you leave a comment, you can check the box (“Save my name, email,” etc.) to tell the publishing software to set a cookie in your browser, so that your information will be already filled in the next time you visit. This is not a tracking cookie of any sort. It is also, regrettably, not an edible cookie. If you attempt to eat the cookies in your browser, you will be disappointed. Dr. Boli uses very simple but effective spam prevention to keep the commercially motivated comments away, and this spam prevention does not involve sending your data to outside servers. (But you may not be able to leave a comment in Russian or Bulgarian if Dr. Boli decides to ban the most common letters in the Cyrillic alphabet again, as he did a while ago when the Russian spam was flooding in.)
An update: Dr. Boli’s secretary thought his European readers might be reassured to know that the site has been examined by professionals and found in compliance with strict European privacy standards. The secretary did not specify what kind of professionals had examined the site, but he is usually reliable.