How casual is too casual for a PhD application personal statement? I’m currently writing a personal statement for a PhD application I am putting together and I have the sentence, “Not to be overly dramatic, but when I saw the advertisement for this project I breathed a sigh of relief because...”

I’m wondering whether this sentence is a bit too embellished and casual to have here, because in the past I’ve been told that a personal statement shouldn’t be too formal but it shouldn’t be too casual either.
That sentence already sounds very flippant. Contrary to its name there is very little that is "personal" about a personal statement (and it's definitely not the kind of soul-searching essay you write for college). It's mostly a document to describe your research experience and how the program fits within your vision of a scientific career. You should certainly demonstrate your interest and passion (in a concrete manner devoid of cliches, of course), but I'd rather err on the side of being too formal than the other way around.