>>3231145>How about the meme to use one focal length only while learning the baby steps?There's definitely some validity to this.
1. Gets you very comfortable with one specific field of view. This helps you get a feel for other fields of view--i.e., you'll have a deep knowledge of, say, what 50mm looks like on your camera, so if something's longer than 50mm or shorter than 50mm, you'll have a feel for what that means.
2. It forces you to compose by moving your camera instead of by moving your zoom ring. Using zoom to compose certainly has its place, but it encourages newbies who don't really understand perspective to think of different focal lengths as a way to get different amounts of stuff in a photo rather than to think of them as a way to get different perspectives on a scene.
3. Limiting your artistic choices in one axis (i.e., focal length/perspective) lets your brain concentrate more on others (e.g., exposure, framing, composition, timing, etc).