Grandpa explaining how he paid for his first car is not a lecture. It’s directions from someone who walked the road.

Older people explaining how they managed something are usually not showing off. They walked a road that has changed in its details and not in its structure, and the arithmetic of saving for a thing, waiting for it and paying for it still works roughly the same way. Hearing that as a lecture is how you throw away free information. The format is dull and the content is unusually useful.

Ask somebody in your family how they paid for their first big purchase. Get the actual numbers and the length of time. Then set it beside what you are currently doing with your own money.