Regular everyday people seem to like the ms - agents don't fall in love with it.
it's enough to make one want to tear their hair out, but i dont' look good bald.
I've read your original post and replies to it. If an agent returns your submission and says such generic things as <fresher, bigger, re-write I'll be willing to take a look at it again...etc> -- move on to the next agent.
Even if you could figure out what they meant (and chances are you won't) by the time you re-wrote and re-submitted he would have long forgotten about you, would have moved on and/or hired a new assistant who'd not know you from adam and you'd get a pre-printed meaningless slip.
But if the agent actually gives your specific input -- which means he will essentially return your material rigorously edited and will give you a DEADLINE by which to re-submit, and asks you to call him to report on your progress (most improbable scenario) then it's time to re-write and re-submit.
There is nothing wrong with your opening line/hook. Move on and find an agent whose eyes are not as tired as this one.'s.
Conversely, if it still bothers you that much that he/she said <fresher, bigger> then find in you story as many elements as you can that are UNIQUE - meaning no one in your genre has done them before (which means you're reading your genre and are up on what's new, what's coming and what's stale). If you can do that, you're way ahead of the game. Then use those elements to pitch your novel.
If you can't do it, then continue searching for an agent who'll like your writing style and your characters since plot would be indeed <not-fresh>. Best regards.