We often find ourselves in stressful or difficult situations, we are constantly bombarded by external worries, and we think it is difficult to deal with our problems. However, no matter how big external issues are, the way that we ultimately interpret these problems is up to our mind. At times we might find a dark joke about death incredibly funny, and at other times it may make us cry. Meditation takes a break from dealing with these interpretations of the world for a moment (instead concentrating on something basic like breathing) and in doing so, gives us a way to acknowledge the fact that our interpretations of the world are all in our head. So even if we can't extend full control over them, these thoughts and feelings are still ours and we might have some influence over them, and it turns out even briefly having this feeling can affect your mind in the long term.
A side effect of meditating is that you might learn to replicate the sense of "stepping outside the situation" even outside of meditation, allowing you to relax and consider the big picture rationally in intense moments in which you might've been originally felt too caught up "in the moment".