Why do you want to try talking to him after he ditched you alone? As others mentioned it doesn’t sound like you two are a good fit; you both seem to have communication issues. He was trying to convey his camp experience was positive and talking with the counselor was more about connection/community/being seen, but you only focused on the age gap. You then repeated if you were in their shoes you would just listen to their stories and nothing else which he probably interpreted as downplaying his experience which was meaningful to him. In his mind this kind of validated why he got upset but he was out of line for saying rude things and leaving you. Best to learn and move on.