That may sound a little outlandish or even risky, but there is a very real truth behind it. When things are going crazy, those in the 9-1-1 field don't have a great deal of time to ponder every possible outcome or read a binder full of disaster plans to find out what to do.
Under the stress of an active shooter, a tornado, a greyhound bus accident, or a fire the Dispatchers on the team handling that incident must react instinctively and with minimal thought. Those of you who have been in those situations probably know all too well the challenge (or horror) of working with someone or for someone who doesn't understand this. They are wishy-washy, uncertain, or indecisive. Often they do not trust anyone to do the right thing.
There is a simple reason why people don't trust others or themselves to make the critical decisions during times of crisis. They don't know themselves or others well enough to trust. This is why training, learning, and teamwork are so important. Building the knowledge and the skill BEFORE the big day allows you to be able to react from a position of knowledge, not a position of fear or uncertainty.
The obvious parallels are responders in life and death situations. They do not have time to consult the manual. It is the memory of their training, the shading of their experience, and their attitudes and beliefs which help determine how they will react. They will not have the time to consult "the book", and neither will 9-1-1 professionals have the ability to do a research project during the crazy times.
So think about your training, knowledge, skills, and experiences. Do you build these up as much as you can? Do you jot down lessons learned from each shift your work or each major event you handle? Do you share your lessons learned with others so you can gain from what each of you go through? There are many ways to build your knowledge, but they are not all from your own ledger.
This is what it means to "know". You may not have all the answers, but you certainly won't have the luxury of time to do a detailed analysis. If you have taken the proper steps before that crazy day, however, you may not even realize that thinking was and is overrated.