Well, it doesn't have to be really first..first-hand :)
Maybe just a knowledge :)
Small things about babies, a few months old before they start walking or talking. Maybe some rules about adoption. NJ. Traveling and quarantine from doctor's pow.
Paris. Streets, places to go, young people. Not young people. French language, the informal one. Art. The famous cemetery.
WWI and the Western front, WWII and Western Europe.