I'm gonna ramble about this here, since I'm not really sure where else to put it.
Occasionally a piece of fiction will immerse me in it so much, pull my heartstrings to such a degree, that I'll be in a weird, numb sort of mood for days afterwards. I'm not really sure what to call it, but the real world will feel dull and unimportant, I'll be detached from it(more-so than usual), my mind will fill with pondering about said fiction whenever possible, and I'll have sort of 'aftershocks' of the emotions it inspired in me.
I've had this from a few different works in the past that I can remember: Movie-wise, The Hunger Games, which was a major example where I moped around for days after seeing it, as well as AVATAR to a lesser degree.
Some great books can cause it too, like While Angels Dance by Ralph Cotton, Crime and Punishment, and especially Shades of Grey by Jasper Fforde. (Not to be confused with 50 Shades of Grey, ugh.)
There are doubtless more examples that I'm forgetting, I don't have my entire book collection on hand after all.
As you may have guessed, The Last of Us is having the same effect on me. It's different, though, in that as a videogame it lasts for far longer than any movie or book, and this weird feeling has persisted since I started playing through the story a couple of days ago.
Even as I write this I just have this sort of... I don't know, it sounds cliché, but a sort of 'tightness' in my chest.
Maybe that sounds incredibly sappy, but whatever. I had the same feeling after watching The Hunger Games-- oh, and I just remembered, L.A Noire did it too, to some extent. I remember watching the credits all the way through, just listening numbly to the beautiful, oh-so-beautiful soundtrack with tears in my eyes. (Do I sound like a headcase yet?)
I did the same thing just before at the menu screen for TLoU. Just lay back on my couch after completing a chapter, just savouring the title music with this enjoyable feeling of happy exhaustion.
Anyway, uh. Yeah. I did say ramble, right? If nothing else my weirdness should give you a WTF.