I now believe that relationships can be joyful and fun

Somewhere behind this there is usually a before: a stretch of years when relationships meant vigilance, or negotiation, or the low hum of managing somebody else's mood.

Beliefs formed in that period don't get argued away. They get outvoted by evidence. An evening that was simply good. A friendship with no undercurrent. Six months of someone who was easy to be around.

Learning it late is common and not a deficiency. People learn to swim at forty. The water behaves exactly as it does for anyone who learned at six.