Everyone has a different amount of curiosity for different things. Just because someone doesn’t want to know how a carburetor works doesn’t mean they aren’t interested in other things.

Also curiosity can be a luxury. Some people are very focused on following the beaten path because they think it might be safer. Start asking questions and rocking boats and you might cause problems. Curiosity killed the cat and all that. Over a lifetime people settle into their own groove of curiosity and satisfaction.