pablumatic said:

"I am immune to the light."

Ugh.

And Luke is apparently the "last Jedi" 30+ years after RotJ.

Exactly what have our heroes been doing since defeating the Emperor and Vader anyway?

Luke must have been sitting out sulking somewhere by his lonesome all this time. The Rebels still can't manage to stamp out the Empire.

There better be some good explanations for all this, but I suspect I won't see them.

I imagine most of the backstory of what happened within the past 30 years will be in the opening crawl. We may hear bits and pieces throughout the film.