Yeah. Where I'm from, they always say that whenever you hear your name being called or whispered whenever you're alone in the house or any other area, you should never answer back. If you answer back, that would mean you are acknowledging the 'presence'. It's best to just ignore it.
god, this just sent shivers up my spine because i'm remembering hearing my name being called very distinctly, like the one who called was right beside me. except i was alone in my apartment.
This happened to me once when I was studying in my room. It was in the evening around 5pm. There was no one home and the doors were also locked. I had even closed the windows because it was getting quite windy. Some time later, i heard my name being called out in a whisper (it kinda sounded like a male voice). I got goosebumps. I was damn scared, still I opened the door and rushed out thinking maybe my parents had returned home and were calling me. But no one was there. I stopped studying and went to watch TV. Need a distraction.
Also, I've heard that when you get a chill all of a sudden even when the weather is too hot for you to feel cold, it means a ghost had just 'walked' by you.
To those who said MC is dumb for not realizing the obvious ghost thingies right in front of his eyes, please reconsider your thought. I don't know about y'all but back in my home (Southeast Asian here) we are taught to shut our mouth and blind our eyes whenever supernatural events happen which is exactly what the MC is doing. The further you acknowledge those things, they will get more excited to pester you. Ignorance is better than acknowledgement. And also, some said how can MC did not feel weird about how his days go in which he sometimes realize suddenly the days sped up or what nots. In some cases of extreme supernatural, the victims will live very muddle-headedly as their bodies felt like they were going on auto-pilot. Their mind is foggy and they could barely remember anything. This is based on some of the stories I heard from my fellows and my family members myself. They usually black out and can't remember a thing whenever this kind of things happened. So, yeah, MC is right with his approach in this manhwa. Ignorance is a bliss.