A sibling who shared your room knows the version of you that exists at 11 p.m. That person’s real too.

Living in the same ten square feet as somebody removes the option of performing. They heard you at eleven at night, unimpressive and unguarded, saying whatever came into your head. That version is not a lesser one, and having somebody who has seen it saves you pretending the edited version is the whole story.

If you still have that person, keep the line open even when there is no reason to call. Ask about something small rather than announcing news. Where the relationship is complicated now, the witness part still happened, and nothing takes that back.