What a man is hiding when he says, 'I'm not ready for a relationship

It's not about "not the right time." It's almost always about "not her."
When a man truly wants a woman, he doesn't need perfect conditions. He's moving, searching for a way, taking steps.
But when is he not ready?
It means he doesn't want the responsibility that comes with a strong woman. He doesn't want to be tested. He doesn't want to be exposed.
He's afraid of failing. Afraid of not being able to measure up.
And most honestly, he's afraid of her reaction if she sees the real him.
But sometimes a man says "not ready" simply because he understands she's too valuable to play with superficially.
And are you saying "not ready" out of fear or honesty?