Confidence is arrogance if the market doesn't believe the story.
When we show up with something great, something generous, well-executed and new, some people will be suspicious. "Is this everything it's cracked up to be?" The skeptic wonders if we have the standing to back it up.
You're not going to be able to persuade those skeptics. In fact, when you try, you end up dressing up your confident presentation with too many claims and you risk being seen as merely arrogant.
The classic 1984 Apple commercial was beautifully confident. It pulled no punches, it was perfectly crafted and it described a product that some people believed would change their lives.
The 1985 commercial, though, was perceived as arrogant. Without enough to back it up, the skeptic in us said, "I don't want this change*, it's not real." (*the bulk of the market doesn't ever truly want change, because change brings risk and risk brings fear. Give people a chance to avoid change, and they'll likely take it).
The market needs the hubris of high expectations, it's the only thing that seduces some people to embrace change. But the provider (that's us) has to tell a coherent, resonant, true story that touches the right people the right way.