I was playing a friend's (we'll call my friend "M") tabletop roleplaying game in which our characters are (mechanically) comprised of key words or phrases produced during character creation, which as players we get bonuses for displaying through our actions. That's not a great description, so I'll give some examples.
My character grew up in the "Science Bulkhead" of a space vessel, and so had the key word or phrase "Science Bulkhead." This type of system can be seen in many other games, for example FATE has aspects and tags, and to my knowledge Lancer has something similar, where each additional feature of your mech that you bring into a description gives you some type of accumulating +1 bonus.
I've always thought about this as kind of silly, like as a player you're narratively coming up with contrived ways to weave these keywords etc. into your descriptions of things in order to harvest that sweet sweet mechanical bonus. Some of the only examples I've really enjoyed are in Burning Wheel, where you give your character three Instincts that if you can trigger to get into trouble (the example given in the book is "I draw my sword at the first sign of danger", so if you draw your sword at an inappropriate time when perhaps the danger is social in nature rather than violent) you are rewarded with a bit of meta-currency. (The meta-currency might actually be called fate, which is funny in this context).
Anyway, back to M's game.
My friend "J" was playing with us, and J's character had the key word or phrase, "Dreamless." Now, when J gave their character this word, it was with the intent to figure it out as we went along. I didn't realize until we did our post-game debrief that it was an interesting challenge, which was a nice way to recontextualize my stodgy "oh boo this is a contrived narrative." The whole narrative is something we're inventing! So, ever since that game I've been thinking about how much of roleplaying can be contextualized as inventing creative limitations for the self, to challenge one's own, and each other's, ability to... well, roleplay. To tell a collaborative story.
Of course lately I have loved looking at everything through the lens of "Trying something impossible, failing, and appreciating what comes of failure," so you can see that this biases me towards a perspective like this!
My takeaway: When inventing a character for a roleplaying game, of course play something I think I can do, but sprinkle in some beautiful challenges for myself and for the others at the table. Can we together tell a story that contains a character who is dreamless?
It should go without saying that I am also thinking about this in the context of my artistic practice, if you'd allow me to refer to it as such.
Introduce an aspirational idea like "Dreamless" and work towards it.
Promise to resolve an idea that seems impossible right now -- don't try to deal with it right away, because if you can, you haven't chosen an idea impossible enough... and if you can't (and you shouldn't!), you'll only frustrate yourself. Wait for the moment to reveal itself.