I don't remember this being so hard to learn, but then I started cycling in the era of downtube shifters, so dropping a hand to a bottle cage wasn't much different. Practice makes perfect... The advice to move your other hand closer to the center of the bar is good—makes the reach to the bottle not so awkward. And only on flats at first, hills (up or down) would only make something a bit disconcerting into something terrifying
