[9530jh9054ven]

Slight miscommunication here. I'm talking about someone that genuinely has absolutely no interests whatsoever. Even after trying skiing, bowling, hiking, just about every time sport, reading, music in all forms, performance arts, painting, board games, table top games, video games, travel, etc. And everything is dull, boring, uninteresting, and unejoyable.

That's the kind of person I'm talking about

[chii]

In that case, this person might actually have a medical condition of some sort. Humans tend to be curious and that curiosity is manifested as an interest in something.

Either they have not tried everything, or they have imbalances or an illness that makes them feel this way. If this is true, there should be no shame in visiting a doctor or therapist of some sort. Otherwise, depression would set in sooner or later and get worse.

[stumblindrunk]

This person is likely suffering from a mental illness. Start there.