First of all, I KNEW THAT LIST OF THREE THING WOULD COME BACK IN A TRAGIC WAY EVENTUALLY. I don’t think I mentioned that on Tumblr but yeah, I knew VRAINS was one of the more trauma heavy ones and Yusaku was doing the ‘think of three things’ too often for it not to mean anything.
So what it ended up meaning was that thinking of three things is Yusaku’s coping mechanism and way to remind himself that he’s alive. I’m guessing he had to fight for his life even as a child considering the few flashbacks of child Yusaku I’ve seen so far.
Which brings me to the next quote: Yusaku associates thinking with living. Basically having a mindset of “if you can’t think for yourself, you’re not alive,” which explains why he’s so against the idea of an AI having free will, even when an AI with free will is right in front of him.
I can see this mindset of Yusaku’s being further challenged as the show goes on, particularly by Ai, though it’s not going to be easy.