Athletic people tend to say that, but I really doubt it's true for everyone. I have never enjoyed sport - being out of shape it sucked more, but while maintaining a sensible training regime I really dislike it as well. For me it's about as enjoyable as doing housework. I do that too, but not for fun.

The only thing that has helped me is to accept that evolution is a bitch and biology is unfair; I will probably never enjoy working out, but I can do it anyway and find a form of exercise that is kinda okay and allows me to listen to good music while I do it.

For some people, "it will be fun one day" just sets a really unrealistic expectation.