As the planets transit through the Zodiac and form aspects to our personal charts, "happenings" occur. For instance, a Saturn transit brings us practical lessons. We may have an opportunity to get a new job, get married, find a new home, and/or deal with our responsibilities in a very methodical manner. These are all possible Saturn lessons. As Saturn brings our lessons, how we decide to feel about them is indicated by the location of our natal Lunar Nodes, and also, to a large extent, by aspects of the transiting Lunar Nodes to our charts.
For example, if you are fired and have to find a new job, you can react to this experience in various ways. You may feel that this is a wonderful opportunity to make a move that you might otherwise overlook. You may know you probably would not have left your job because of your sense of responsibility to the company, or because you have security issues relative to your personal financial responsibilities. If you hadn't been fired you might have lost the chance for a new beginning! Or, you can feel utterly miserable: Poverty is just around the corner, and how are you going to pay the bills? You get to decide how to feel about any given "happening" in your life!
How or why we feel a certain way about a situation is indicated by current node transits. In the example above, a full understanding of the ramifications of the situation, and an assessment of feelings will end when the transiting North Node conjuncts the point in the chart where the Saturn aspect took place as the event happened.
Where Saturn brought the lesson, the Lunar Nodes give the opportunity to feel something about what was going on. We may avoid feeling something for a time, but the Lunar Nodes will eventually aspect that point, "gobble up" the dot, feed the information into our Moon, and a feeling (opinion/judgement/assessment) will result. . . . .