How I approach the Player Knowledge / Character Knowledge Dilemma in Solo Roleplaying

I dislike separating character knowledge from player knowledge, so if I have a story premise in mind, I will frame things such that I know only as much as the character knows. Otherwise, it would be better for me to be the GM and emulate the players .

One Way To Avoid That Split As a Player

When you're trying to avoid that player/character knowledge split, I think that the #1 thing is being conscientious to avoid omniscience. Anything that your character does not know is something that can't be treated as a fact. It's only a possibility that you as a player know about.

In my opinion, you shouldn't even attempt to confirm or deny a fact until your character is in a position to find out. Just leave it hanging there until such a time.

Hardcore Immersion

If you want to be even more hardcore, consider this:

Some GMs consider in-game player chatter to be in-character chatter.What if you considered your own in-game mental chatter to be in character mental chatter? In other words, if you find yourself thinking of some possibility, you should treat that thought as something that has also entered your character's mind.

Just remember, though, just because it entered your character's mind, it doesn't mean it's a fact. How your character reacts to these thoughts is in itself an interesting roleplaying exercise. Is she/he going to dismiss them as fanciful flights of imagination? Is she going to keep them in mind as a real possibility?

For me, that's going to be informed strictly by what's already been established as confirmed fact during the initial set up of the game's situation, and in the course of play.

If any of this doesn't make sense, or needs some examples, let me know.