you gotta be an optimist...

20+ years ago, when I was about to walk up to a computer for the first time in my life and type in a program, I was told by someone wise (magicmirror) not to expect my program to compile (let alone run correclty!) at the first try. Now, in the middle of a huge code refactoring, I can expand on that wisdom with some optimism:

1. If you modified a program, and it no longer compiles, it is great news - it means that the compiler is actually compiling the modified code, not some copy of the old working code that just happened to lie around for some obscure reason!
2. If you got the modified code to compile but it fails to run correctly, it is great news - it means that you are running the modified program and not an old working executable that just happened to lie around for some obscure reason!

By extension, if everything works just fine, go get some coffee and check what you are doing step by step, and you will find an error!