This excuse is gold because it allows not only you, but everyone else to let you off the hook. Most people will sympathize or corroborate your ironclad reasons for not taking action yet. (Could it be because they’re stuck themselves?) The problem with “I’m not ready,” however, is that it assumes there is some magical time off in the future when you will be. But there isn’t.
Even if you earn more money, get more experience, or “settle down,” you still may not feel ready. Because it’s not really about those things, anyway. It’s about your relationship to fear, change, and the unknown. By all means, prepare before you leap. But don’t spend too much time preparing, or you may find yourself in the same spot a year—or ten—from now.