Yeah, I know what you mean. I have written and rewritten first sentences and still hate them.
@Dawn_McClure and I have had a lot of conversations about how important they are. She is of the opinion that you have to start in the "normal world" so that means the first couple of pages are setting the stage, where I go for the BIG WHAM. Now Dawn actually has books published and sells them while I am, well, still working on that.
I can tell you as a reader that I have never stopped because the first sentence was not memorable. And I read A LOT. If I am going to pitch a book in the dustbin, it's because it gets lost about midway. The book I am reading right now is one of those, the first chapters were great but then it's wandered off, and totally lost any motivation or plot.
(The Long Way to a Small, Angry Planet (Wayfarers Book 1) by Becky Chambers). Fabulous premise, funny set of quirky characters and a good first chapter but man is it lagging.
I just reviewed the first line of the last three books I read. None of them were in any way memorable.
Hmmm
So IDK ¯\_(ツ)_/¯ Maybe that epic first line is really not necessary.
YMMV