I imagine a lot of New Yorkers were visiting their psychiatrists when the Fantastic Four first turned up (and weren't well known). Seeing objects floating the air, clearly hearing voices talking to you, feeling like you've been shoved to the ground where there's no one within reach.. well, it's time for some medications.
We're so used to seeing bysstanders in comics (and horror or sci-fi movies) do a comic double-take after witnessing something uncanny, it's a bit startling to wonder if these people worried the rest of their lives if they had schizophrenia and needed medical care. Ah, better not to think about it, the cliche's just meant as a bit of humor.