I wonder how easy or difficult it is to find out who I am, using information security's most advanced techniques. And what can I do that will not affect my browsing experience too much, as a lambda internet user, against that?
Yes, there are many ways that your ISP, your DNS provider, the web sites you visit, third-party content providers, advertisers, government agencies, etc. can track your web browsing and identify you. The methods that they use are based on your IP address, cookies, super-cookies, browser fingerprinting methods, and the like.
If you do not like the experience of TOR or other routing networks, you can enable some browser plugins which give you an idea of who is tracking you and prevent them from doing so. The Electronic Frontier Foundation has a handy plugin Privacy Badger which you can use to visualize and manage various trackers on a site-by-site basis.