For the majority of math history, people wrote proofs using natural language. Formalized notation is relatively recent. I have read both, and the notation is (o

For the majority of math history, people wrote proofs using natural language. Formalized notation is relatively recent. I have read both, and the notation is (on the whole) so much easier to read. But anybody is free to learn math beyond an undergraduate level with natural language texts. If you want to be traditional, start with Euclid's "Elements." Plus, in the good articles I've read, the structure is usually: dissection of subproblem, intuitive description of solution, converting that solution into notation, proceed to next subproblem. If you see an unfamiliar symbol in an article, look it up. If you don't understand its definition, you don't yet have an intuitive grasp of the concept. Keep going down that rabbit hole until you have the intuitive building blocks to understand the article. Frankly, I love how much math we can teach before a kid graduates high school. Thousands of years of mathematical ideas, up to calculus invented less than 400 years ago. All before they're 18 years old and probably don't care much about math.