The Post-Movie Blues

I just saw Parasite (2019) and I'm feeling down. This seems to occur after I see most good movies. To be clear, Parasite was fantastic. A near perfect movie in my book; incredible story-telling with all around great performances, clean and pretty cinematography, and the ability to evoke a near-constant sense of tension and concern. But when I see a great (or even just good) movie, I'm suddenly left with feelings of sadness. I still appreciate the movie of course, and this is usually coupled with or proceeded by awe or appreciation for the craft. Weird, right? I believe the feeling could be categorized as a longing for what I've seen: grand purposes, the sense of importance, or even just the interesting and often life-altering experiences of those depicted. And it's not just when the movie has a happy ending or when the main character succeeds in their goals. Even when the outcome is grim, I can still encounter this want for the escape from the mundane and normal(It's hard to say if that is exactly what it is for sure).  The grass is, of course, always greener. I likely wouldn't like it if I got whatever it was exactly that I feel like I'm missing here. At least that is what I am led to believe. Maybe this is only something you can observe from the outside?