The only allusion to persistence seen in the trailer is what happens to Strange's hands, but without giving away a bunch of spoilers, I can attest that a lot of the movie, especially the final scenes, are an ode to the necessities of persistence--and how it can pay off. Especially when the word NO feels like this:
There's a quote I heard recently, one that I'll paraphrase the best I can. Instead of seeing rejections as negative roadblocks, think of them as necessary hurdles of no's before you get to the finish line of yes.
So keep persisting. And if you need a bit of motivation, Doctor Strange can help.