We are trained as firefighters and EMS through repetition so that when seconds count we don't have to think about how to accomplish a task, we just do it. From donning our breathing apparatus to drawing specific drug dosages it becomes second nature and we do it without thinking about it.
We become sort of robots that are trained to block out our own emotions and the chaos around us to perform at our very best.
Some of us have become very good at using this ability to block out chaos and our emotions to accomplish a task. I used this ability to speak at my sisters funeral and to be there for my family during their time of need. It can be very useful when you don't have time to process your emotions at that specific moment. The difficult part of this process is remembering that you must eventually come to terms with those emotions or they will come back to haunt you.
In emergency services, this process of coming to terms is called CISD Critical Incident Stress Debriefing. It's a process of releasing this huge volume of stress and emotions in an appropriate way. After a particularly difficult call, a CISD team will be called in to work with the group to release the suppressed emotions. It's an important step in supporting the emotional needs of our emergency services workers.
The takeaway in this is that everyone processes events differently. Don't judge people by the way you see them react, they might be delaying the emotional processing until a later date