Let's take a look at a couple of instances in the Bible, where we see first reactions.
First, let's look at Moses. In the book of Exodus, chapter 3, you can read the story of Moses' call from God to deliver the Israelites from bondage in Egypt. In that story, you see where God spoke to Moses from a bush that was on fire but was not being consumed. As God spoke to Moses, He called him to deliver the Israelites from slavery in Egypt.
What was Moses' first response? In verse 11 you see were Moses asked, "Who Am I, that I should go to Pharaoh? Moses' first response was that he wasn't the person to go to Pharaoh. His self-image was low.