Wisdom of this kind rarely arrives as insight. It looks more like knowing, without being told, which forms to fill in first, or how to sit with someone whose father has just died and not fill the silence.
People who have been through a great deal are usually quieter about it than expected. What they carry is practical: where the exits are, how long a night takes to end, which offers of help are worth accepting. Nobody would have ordered any of it. It is, all the same, genuinely useful to the next person who needs it.