Lydia Ko is too good to be true. She is so good that golf aficionados speak their mind in hushed tones, or behind closed doors.
This is why: Lydia Ko can become the greatest woman golfer of all time, or at least modern times. This has to be a possibility for anyone who has done so much at such a young age.
But we're wary of saying things like that, in case it doesn't work out or puts unreasonable pressure on a prodigy. This is also unfamiliar world sporting domination territory since the demise of our exceptional middle-distance running.
Maybe Ko is so outrageously amazing that we can't come to grips with her potential. She seems too nice, too chilled, to be that driven and competitive. Her rise takes us out of a comfort zone, the more familiar world of men's professional sport.
Ko's first LPGA victory as a professional this week made it easier to see the extent of her future and thus more nervous about acknowledging it. Lydia Ko is off-the-planet good. When Ko is on the leaderboard, watch out.
The only thing that might stop Lydia Ko is Lydia Ko, who has talked of going to university. Barring the unimaginable, she will win a clutch of majors and can join the short list of women who have played in men's tournaments.
Ko is on track to becoming the most famous New Zealand sportswoman, or sportsperson. The female candidates, essentially Olympians, come from niche sports that grab the spotlight only now and then. As good as Valerie Adams is, she won't figure highly on ESPN. No matter how good anyone is at the shot put, they will never knock tennis and golf off the world's back pages. Try this for a good argument - Ko can become our most successful pro sportsperson ever.
The pecking order in women's golf is not as famous as the men's game, where Jack Nicklaus reigns and Tiger Woods is the man who was going to be king.
Women's golf does include a truly remarkable figure, Babe Didrikson, the cross-sports freak of the 1930s, 40s and 50s. The American won 10 golf majors plus two Olympic golds in track and field and nearly a third. She also made the PGA golf cut against men. Ko won't get close to that legend because nobody will. But that is not just a golf issue.
Swede Annika Sorenstam is perhaps the finest women's player ever. Given the improvement in depth and standards, the best of modern times deserves to be called the best of all time. Sorenstam has 10 major victories, and Ko can top that.
The Ko story so far is stunning. The 17-year-old has beaten the best professionals as an amateur, and has already carried on her winning ways in the pro ranks. Controversies have been quickly overcome, even though a taxpayer funding row not of her making unnerved the teenager. Some knew better about a coaching switch, but Ko's victory in California laid that complaint to rest.
Ko smiles like a kid, and shoots like Billy the Kid. Her composure and toughness amazed seasoned onlookers yet again. Her putting appears on the necessarily steep improve. Ko even won her first LPGA title as a professional minus her very best game.
What might stand in her way? Burn-out. Levelling out. A crop of new stars. The putting yips. Hurdles unforeseen. The week in, week out hurly-burly. Nah - forget all that. This is the time to dream sweet dreams. Ko could take women's golf to new levels of fame, rather than the other way around. As good as this story already is, an amazing best is yet to come.