I think we all have at least one fan theory each of us believes is true. So let's share them here. Whatever isn't officially canon (maybe yet) but makes enough sense to be headcanon. Just pure speculation to help a narrative and bring things neatly together.
I wrote a post about two years ago listing my five favorite fan theories at the time. Soon I'll revisit each one and make them posts for this community.
Photo Source: theguardian.com