Strong solipsistic belief can turn to paranoia or even pronoia depending on what might be happening in a person’s life.

Pronoia can then unexpectedly turn to hubris.

Source: I occasionally go off on solipsistic flights of fancy, but then have to reel myself in.

Much like predestination, it’s probably not healthy to do nothing / potentially wrong things and assume everything will fall into place.

I learned this one from Solipskier! One of my favorite little flash games from back a few years ago: https://www.kongregate.com/games/Mikengreg/solipskier?acomplete=solipskier