If your boss disagrees with you, he can do the work his way. But would he? He can argue however he wants but if you’re the one who will do the work, you win the argument.
Likewise you can have a friendly discussion with friends about various business ideas and they could have concerns about your ideas that are well-meaning. But eventually you’ll be the one to test out the hypothesis. Of course, if they try to test it for you and confront you with the results, you should be heeding them.
The conclusion is the same, that you win the argument eventually when you do the work; not by being right.