It can be anything: an actual "thing" you're afraid of, a scenario, a situation, ANYTHING. But, when it comes down to what you're TRULY and deeply afraid of, what is it? Mine is unquestionably the notion that I'm going to die and that all the people in my life are going to have very unrealistic conceptions of what they meant to me and how they affected me. For example, if I were to kick right this instance, I suspect there's a great deal of people in my life who presume that they are very significant to me and mean a great deal to me while that is not the case. Conversely, there are likely a few that, while they shape almost every aspect of that which is truly important to me and nearly everything in my life that matters finds it roots in them, likely imagine that they are nothing more than individuals with whom I converse casually and/or blithely. For whatever damn reason, it scares the hell out of me that people might carry on the rest of their lives with these misinformed perceptions (on either end of the spectrum)....that happening makes me feel as if my entire life would have "missed the point" or something like that.
Getting eaten by a shark, is, however, a close second to that existential "hiccup".