Ah yes - the person who really, really cares about the Project. It's their baby, their idea, their organization, their dream. They may not have a clue how to pull it off - but they sure know what they want - and it's the job of the rest of us to help them do it.
Before every great success was somebody's bright idea of how to solve a problem, provide a better way, enlighten the world or just have some fun. Imagination, drive and determination - and a whole lot of nagging and pushing of other people - are what makes the world a better place though innovation ---- or even by reinventing the wheel which probably should have somebody take a serious second look at it.
Many Owners are very protective of their project - but many are not that good at managing projects or turing ideas into cash. A good Project Manager is worth her weight in gold (especially if she's a tiny little thing.)
addendum:
If you are the Project Owner - then you should find a suitable Project Manager first;
"suitable" as in - your Project Manager (PM) should be the one who knows what kind of resource people it will take to get your project done on time, on budget and with the biggest bang for the buck. Let the PM deal with selecting people, negotiating contracts, cracking the whip - etc. - all you have to do as PO - is sign the cheque.