He was in his own subjective reality and didn't really care anymore.

他沉浸在自己的主观现实中，不再关心（是梦还是现实）了。

Again, because of our subjective realities, whether something appears problematic differs per person.

同样，由于我们的主观现实，某件事是否是问题因人而异。

I am sure will startle you as you become more aware of your own subjective reality.

当您越来越了解自己的主观现实时，我相信您会大吃一惊。