Bike repair turned into a whole thing

My son's bike had a flat tire so I figured I'd just patch it quick. Took the wheel off and realized the rim tape was shot and the tire was basically done. One thing led to another and I ended up replacing the chain too because it was rusty. What should have been 30 minutes turned into 3 hours in the garage with my son watching and asking a million questions. He's already asking when we can fix his sister's bike now.