Every time I delve into the internals of the .NET Runtime, I am somehow aware that I don't really know that much and I marvel at the ingenuity of the Engineers who wrote the code! :-)
Especially in this post, the crazy, low-level tricks that the Profiling APIs and the Debugger have to do are amazing, for instance read 'How do Managed Breakpoints work?' https://blogs.msdn.microsoft.com/jmstall/2004/12/28/how-do-m...