Yeah, the "dead silent like a library" thing is too real. I tried smiling at someone once and they just adjusted their noise-cancelling headphones. It somehow made me feel more alone than my empty apartment. I guess the vibe really depends on the specific space and day.

Watched my buddy ignore a faint grinding noise in his car for way too long. He kept saying it was probably nothing until his brakes gave out on the highway. Thankfully he was okay, but the scare made him get every little sound checked now. He even set up monthly check ups for his car, which he never did before. It's like you said, sometimes we need that wake up call to start doing the right thing.