Generally agreed, except for the "Anyone" - because people really are different. I'm familiar with a few people (from very young to adults) who are extremely one-handed. The other hand is nearly useless, except for holding and supporting. Those individuals will typically turn newspaper pages or book pages using their right hand (if they're right-handed, and one guy told me that he didn't trust his left hand with a fork to actually hit his mouth, so he used a knife+fork the opposite way of most right-handed people. These people are in a minority, but they exist.

Then there's guitar.. some, or actually most left-handed people can learn to play a right-handed guitar if they simply start with a right-handed guitar. But there are also some people (some of them very well known) who tried learning the guitar for a very long time, and couldn't. Until they switched to a left-handed guitar. (Why it's natural to actually use the left hand for something which looks complicated - fingering, and the right hand for something simple - strumming - has been discussed forever. Apparently that's because a right-handed person typically has better timing in their right hand, and that's why it matters).