Your grandparents are walking libraries. Ask a question and listen to the whole answer, even the long version.

The long version is the content, and impatience edits out the best part. Ask what a job was like and the useful material is in the digression: the man who ran the place, what a week’s wages bought, the thing nobody would believe now. A short answer gives you facts. The twenty-minute answer gives you what it was actually like to be alive then.

Ask one question this week and do not interrupt once. Record it on your phone if they are comfortable with that, because this is a library with no second copy.