Easy enough. Consider the usual setup for Zeno’s Paradox: A runner is stationed one mile from the finish line, and the race begins. Before he can reach the finish line, he must first reach the halfway point. But before he reaches the halfway point, he must get halfway to the halfway point, and so forth.
Zeno argued that this led to an infinite regress and, since he rejected infinite regressions, he concluded that motion is illusory. Assuming that you agree that motion is real and not illusory, it would seem that you are forced to accept the existence of infinite regressions.
Again, I suspect the real issue here is the question of what counts as an “event”. In this case, we have an infinite sequence of events, and each event is defined as getting halfway through completing the previous event. There is no “earliest event”, hence the regression. Can events be defined recursively in this way? Can they occur over arbitrarily small time intervals?