JavaScript's type coercion strikes again. Someone tried to compute the Fibonacci sequence but forgot that adding strings together doesn't do math—it does concatenation. So instead of getting 1, 1, 2, 3, 5, 8, 13, you get "1", "11", "111", "1111"... just progressively longer strings of ones. It's like watching someone try to do arithmetic with duct tape. The best part? The code probably ran without errors. JavaScript just silently nodded and said "yeah, this seems fine."