Some people are just built different, and the thing with max spookiness is I feel you wear out the horror by getting accustomed to it too quickly. Mortuary Assistant is at its best when it's able to slowly build tension and atmosphere rather than playing like a cheap thriller. Gotta have someone meeting it halfway by getting in to the right mood, and honestly turning off story spooks imo because they're too on the nose.
Anyways this is an excuse to post two of my favourite playthroughs, Rap God Enna and Fauna's concerning heart rate: