During our childhood and youth — in these narcissistic times, we can tell ourselves that youth extends beyond 30 — we are the player-character in our own lives. We can chug through the huge open world we call Earth and, if we are privileged enough (if you're reading this, I can assure you, you are) be the centre of whatever world-saving, prince-or-princess-rescuing, trophy-attaining narrative that's been laid down in front of us. All the quests are ours to accomplish, the villains ours to defeat.
Everything revolves around us, basically.
I think RPGs appeal to us because they affirm this belief completely. Only you can save the world from the giant evil that is threatening imminent apocalypse! But yeah, if you wanna have a gap year exploring caves, hanging out in a cellar summoning and punching skeletons, or even just chasing butterflies, that's cool, we'll just be at this quest marker until you're ready. By all means, make some more gloves. Become head of the Thieves' Guild. The apocalypse can wait.
If you're lucky enough, programmed in such a way, or whatever it is that predilects some humans to find a long term partner, and you're OK with that, you start playing co-op with another PC. You realise (perhaps begrudgingly at first, until a distilled shot of Sesame Street ethos percolates into your consciousness) that the world is to be shared and that things are way more fun with someone on the couch next to you, experiencing the level. That's not to say there aren't some frustrations around hoarding powerups or griefing, but hopefully these too can be laughed off before ragequitting occurs.
Then you have a child, an event that is culturally and almost biologically designed to deliver you an epiphany. Because I have played hundreds of hours of RPGs, my epiphany was framed a certain way: I'm not the PC anymore. I'm the NPC in my daughter's life.