Why is my friend of 30 years so sure I’m lying about my educational degree?

DEAR ABBY: A longtime friend recently accused me of lying about my education, and I’m still stunned by it. I completed my undergraduate studies in the U.S., earning a BA, and later earned a master’s degree from a French university.

Recently, during an exchange on Facebook, my friend asserted, quite confidently, that I was lying about my academic history. When I corrected her, she doubled down and said that because of this, she wanted to cease contact with me.

While this is upsetting given that the accusation is false — I did finish college, and I do have a graduate degree — I am less distraught by her ignorance than by the certainty with which she accused me and the implication that I’m dishonest. I’ve always been straightforward about my background, and I find it unsettling to have my integrity questioned by someone who has known me well for 30 years.

My dilemma is this: Do I owe my friend proof or an explanation beyond what I’ve already said? Or is it reasonable to refuse to defend facts that are true? It seems crazy to lose a friendship of 30 years over something I consider to be so trifling and, quite frankly, stupid. And yet, I’m not sure I even want to be friends with someone who would treat me so callously. What should I do?

— WRONGLY ACCUSED IN NEW YORK