At first I wasn’t sure how much I agreed with the ravers about Richard Linklater‘s Before Midnight, the third (and final?) Ethan Hawke-Julie Delpy exploring-all-things relationship flick (following ’95’s Before Sunrise and ’05’s Before Sunset). I felt intrigued and highly stimulated by this deep-drill, naturally flowing talkfest…but not entirely sold.

But everything changed with the final sequence of this Greece-set film — a one-on-one confrontation of ultimate marital truth in a hotel room (and then outside the hotel at the finale) lasting…oh, roughly 35 to 40 minutes. This is what brought it all home and convinced me that Before Midnight is not only the finest film of the 2013 Sundance Film Festival so far, but the crowning achievement of one of the richest and most ambitious filmed trilogies ever made.

This final portion couldn’t be more primal. Every marriage and serious relationship in the history of post-’60s Western culture has had to deal with this stuff — the comfort of knowing your partner really, really well and the need to accept (and hopefully celebrate) all that he/she is, persistent divorced-parent guilt, the onset of pudgy bods and middle-aged sexuality, dashed expectations vs. the acceptance of real-deal trust and bonding, unfortunate eccentricity and craziness, fidelity, personal fulfillment vs. marriage fortification…the whole magillah.

If there’s any sensitivity and receptivity among the industry rank-and-file, Before Midnight is an all-but-guaranteed contender for writing and acting awards a year from now.

That’s as far as I can go with today’s screening schedule hovering like a hawk, but this, it seems, is the Sundance ’13 film most likely to walk away with an assortment of Jury and Audience awards, and almost certainly the most critically acclaimed and successful Linklater-Hawke-Delpy film once it opens commercially.