The Sacred Four Spaces Of Indentation

When your code doesn't work but your colleague's identical code does... turns out they used 4 spaces for indentation while you're a tab heretic. The compiler/interpreter bows to the spaces like that stubborn child listens to grandma. Nothing triggers holy wars in programming quite like the tabs vs. spaces debate. And somewhere, a senior dev is silently judging both of you while writing single-line code with no indentation whatsoever.