You’re paranoid (competitors, employees, partner will steal your ideas) – a commercial banker told me he sees this more often than you’d think.
You’re waiting; for the economy to improve, the idea to develop fully, the approval of others.
You can’t trust your feedback loop; accounting or other KPI’s are giving you mixed signals.
You’re afraid; of failure, of embarrassing yourself, of commitment.
Groupthink; your employees, spouse, partner, or banker all think every idea you have is great.