When I think about the time I spent in the VC++ debugger tooling around through the MFC code to see what it was really doing as opposed to what I thought it was

When I think about the time I spent in the VC++ debugger tooling around through the MFC code to see what it was really doing as opposed to what I thought it was doing... Yeah, bugs came from my "inability to understand the code under all program flows", or whatever, but it would have been considerably more difficult to understand the code without looking at it in use.