Stopped scoring movies halfway through, my ratings make more sense now

My buddy Dave who runs a film podcast told me last spring to stop keeping a mental score during the first 30 minutes of anything I watch. I thought he was being dramatic, but I tried it with a slow Korean drama on Netflix and it totally worked. Before, I would lock in a 6 or 7 by the halfway mark and then feel stuck defending it even if the ending blew me away. Now I just jot down notes in my phone like "camera work weird" or "that laugh felt forced" and wait until credits roll to pick a number. It made me realize I was scoring my own mood, not the actual movie or show. Has anyone else had to train themselves to hold off on rating until the final scene? What do you do when a thing starts weak but finishes great, do you average it out or just go with the last impression?