My grandma taught this lefty to knit when everyone else had quit. She taught me that maturity is beautiful and a worthwhile lifetime goal. Mom insisted on thank-you letters and never failed to drill in to us that they needed to be letter-perfect ( grandma was a retired schoolteacher). Being letter perfect hasn't hurt me, nor the habit to say "thank you".
Grandpa taught me that you don't always have to do what Grandma says (he'd simply turn down the hearing aid). Grandpa imparted the joy of telling a good tale and living until you drop.