“Born alone” is beyond reductive, it’s plain wrong. You literally come out of another human who you must then feed on for months in order to survive.
This is the trick of the universe, or a trade-off if you will: being completely alone also means being completely free in terms of internal experience. If you realise that - that is the greatest gift, if you are unaware it can feel like a curse.
I'm saying that others can't understand you fully, not just the mind but whole combination of memory, emotions, experiences, etc. Therefore being alone is not different from being surrounded by other people, I'm not saying they don't exist or anything like that.