The first line of the book

Knowing that the publishing date of 'The Ghost of Crow Cavern' is drawing near. I decided to set up some practice Q and A sessions with some of the English groups that I teach, in order to prepare me for any such future events.

I learned a few things from these practices. The one that really comes to mind is that the same question was asked by 3 different groups that I did not have the answer to. The million dollar question was:

''What is the opening line of your book?''

How embarrassing that I did not know. So, after being asked I had to check the manuscript and it was as follows:

''For what seemed like all of Cheswick's tender years, outlandish rumours had been told of a looming visit from across the uncrossable sea.''

Then I started to think/over-think, is this opening line good enough? Does it have the required - whatever it is that an opening line should have?

Here are some opening lines from some famous books:

Call me Ishmael. ----Herman Melville, Moby Dick

It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife.'' —Jane Austen, Pride and Prejudice(1813)

It was a bright cold day in April, and the clocks were striking thirteen. —George Orwell, 1984 (1949)

So, what is it that makes a killer opening line and should I have messaged the publisher to make yet another revision?

Would appreciate your insights