This. I tanked an interview once because the problem was phrased in a way that it wasn't apparent to me that it's basically a graph. Once I realised that it was

This. I tanked an interview once because the problem was phrased in a way that it wasn't apparent to me that it's basically a graph. Once I realised that it was also clear why a simple BFS would solve that problem. Sadly this happened just as the interview was over. I think I sort of blacked out because I couldn't identify the underlying problem, and my mind "unlocked" the moment that the stress of the interview ended. Which reminds me - another important thing is not to get stressed if the solution is not apparent immediately.