What makes you feel someone Really knows you?

[Animal]

Obviously, knowing someone inside and out requires spending time together, talking, sharing inner world, trust and myriad other things. But my question is: if you look back into your past, which experiences made you feel the absolute closest to someone? What made you feel like someone REALLY knows you? You can also judge this by asking yourself, what WOULD make you feel most known, understood and seen?
I'm only allowing one option. Unfortunately we don't have the tools to "unvote," so for now, your votes are permanent. Pick one. It's ok if you change your mind later - I want your GUT HUNCH, right now!
Most people will say "ALL OF THESE!" but which option is MOST crucial? What is the MOST necessary component for your dream partner or dream friend? Please elaborate in the comments, if you so choose!

You may only choose ONE. The most important one. If others really stand out, please write in the comments.

Also tell me if I left out anything.

[Animal]

For me, several of these are important. I could divide them into a few categories.

The top sentence in each group is the most important part, the "head" of the category. The points beneath are all things that follow from there.

1. Sharing a separate or parallel reality, a highly personal "home planet."
- Exploring each other's innermost fantasies, interests, thoughts, and feelings.
- Exploring God or religion together.
- Mental sparring, challenging, arguing together.
- Sharing secrets that no one else knows.
- Exploring deep fantasies, fears, and psychology through sex.
- Exploring altered states of consciousness together.
- Inspiring each other artistically.

2. Making a public statement together, being a 'power couple.'
- Leading a movement together.
- "You and me against the world." Taking on the world together.
- Fighting against injustice or misinformation together.
- Dressing up, sharing fashion together.

3. Surviving hardship together.
- Healing together, inspiring each other to heal.