Excitement can be sincere while still being premature.

Meaning it does not make it ready. Real enthusiasm about a plan, a person, or a possibility says something true about your interest, and it says nothing about timing. Announcements get made, money gets committed, and identities get rearranged around things that would have been fine if given another two months to prove themselves. The sincerity is what makes the prematurity so hard to see.

When you are certain about something new, distinguish between believing in it and building on it. Let the belief run free. Delay the irreversible parts, the telling everyone, the spending, the quitting, until the thing has survived a little ordinary time.