That is my Aha moment too, but I have generalized to: Never start real work, until you can set a breakpoint in your IDE, where you can try things in the console

That is my Aha moment too, but I have generalized to: Never start real work, until you can set a breakpoint in your IDE, where you can try things in the console. I know there are people that can write code for couple of days without running it (seen this with some java colleagues I've had), and then it all almost always works when run, but I am just not that kind of developer.