why have i never heard this as a sermon?

"Now Moses was keeping the flock of his father-in-law, Jethro, the priest of Midian; and he led his flock to the west side of the wilderness, and came to Horeb, the mountain of God. And the angel of the Lord appeared to him in a flame of fire out of the midst of a bush; and he looked, and lo, the bush was burning, yet it was not consumed. And Moses said, "I will turn aside and see this great sight, why the bush in not burnt." When the Lord saw that he turned aside to see, God called to him out of the bush, "Moses, Moses!" And he said, "Here am I."" - Ex. 3:1-4 (italics mine)

We hear of Moses checking out the burning bush, and GOD speaking to him, and that's the happy story of "Wow. GOD spoke to Moses, and Moses eventually, after many 'but's, obeyed."
But here's what happened. The Angel of the LORD appeared. He came on an ordinary day as Moses was doing an ordinary task. He didn't speak. He didn't come before Moses. He made Himself noticable, but not in a way that Moses couldn't ignore. Moses had to turn aside to see the miracle that was happening. He had to conciously make an effort to see what GOD was up to. He could've kept going on with his daily tasks. He could've taken a moment and thought, "Wow! Look at what GOD has done!" and walked on past. But he didn't. He chose to take the time and effort to explore GOD's wonder. Until he did that, the LORD did not speak. The LORD let Moses know HE was there, but HE did not impart HIMSELF to Moses until Moses sought HIM. Yet as soon as Moses did, GOD called to him by name.