And despite my knowledge , I did not do everything according to the briefings
That's why they are briefings, situations are not always as the briefing covers, and there is not always time. Brief to keep your mind agile, then use your agile mind to make the best decisions that time and circumstance permit. If everything were perfect, a safety briefing would not be necessary.
But line things up for your best outcome as early in the [pre] flight as possible.