This applies to so many things in life .... what is major for one person, and quite minor for another, doesn't diminish the stress it can cause. It is also interesting that experience helps one set the distinction between major and minor. We see this in our kids all the time.
What is critical and important to our kids is no less critical and important to them than the most important issue that we, as adults, face in life. So, the trick is, to recognize this when the next major event occurs and try to put it all back into perspective. Short of life threatening situations, nothing is ever really major.