but since you all suck:
Wow...
Deep shit.
Real deep.
I think this is kind of an existential work - trying to find meaning and purpose but yet at the same time, fears change, even though it is imminent. It's a reflection on life and the choices we are faced with, but you've put your signature darkly-lit twist on it to make it much more ominous.
Very enjoyable.
I think it does matter what is in the box but I absolutely think we don't need to know. I think it's much better if whatever is in the box remains ambiguous.
I think whatever is in the box would be unique to each reader. I believe that whatever is in there is whatever gives the reader contentedness - it's whatever we've been searching for - peace of mind, happiness, wealth... whatever it is, I think it would mean something different to each and every person and therefore I think the poem's stronger for not stating what was in the box.
I'm not great at analyzing poetry - but I gave it a go. I loved it.