There's a bit of that in Blue Ruin, too. A gun nut who may have had some experience killing people advises the main character not to give any big speeches before blowing the bad guys away. Just pull the trigger and move on with your life. When the main character fails to heed this advice, it almost gets him killed.
Blue Ruin was one of those movies I really wanted to see, but it somehow slipped through the cracks for me. (I assumed Blue Ruin was Saulnier's first film, but it turns out he made a movie called Murder Party first; I'll be catching up on that one sometime this year, too.) Now that I've seen it I can say it's one of those movies I live to see. Maybe I didn't like it as much as I currently enjoy Green Room, but I have a feeling this one will grow on me as well.
Macon Blair, who plays the wildly bearded Dwight, is first seen soaking in a bathtub. When he hears a noise in the house he leaps through the window like a startled raccoon. It turns out Dwight doesn't live here and the people who do have unexpectedly come home. Dwight actually lives in a beat-up car just off of the beach, which is where he's been living ever since his parents were murdered. Since he leaped out of the stranger's tub with nothing more than a bath towel, we learn early on he's an expert at acquiring clean clothes. This is a skill which will prove useful more than once throughout the movie because things are going to get very bloody.
I didn't know who Macon Blair was before this movie. He's already becoming one of the my favorite actors.
Long story short: it's an extremely entertaining crime thriller which examines the self-destructive nature of revenge (and blah blah blah) without becoming the least bit preachy. And if you want to know more about the plot before seeing it, see any other review, but I'm telling you: if you like grizzly crime movies, this one's a winner. There's really nothing else you need to know before seeing it.