0.9999. . . = 1?

(((I don't understand why this is and it hurts my brain.)))

Link

In mathematics, the recurring decimal 0.999… , which is also written as or , denotes a real number equal to 1. In other words, "0.999…" represents the same number as the symbol "1". The equality has long been accepted by professional mathematicians and taught in textbooks. Various proofs of this identity have been formulated with varying rigour, preferred development of the real numbers, background assumptions, historical context, and target audience."