Pretty common antonyms in this context, both for the literal denotation and figurative connotation, are:
In particular the first two, deep and profound, carry the literal dictionary definition (per Google):
noun, literary: 1. the vast depth of the ocean or of the mind.
Regarding the sentiment you're expressing with "real", you may prefer:
Which have all the gravitas due polysyllabic words (though I'd argue people using the straightforward and common real are more, well, real).
If these don't suit, they'll serve as good entry points for a thesaurus search.