Elegran - discretion as the relevant noun - that confuses me even more!
"The root of both “discreet” and “discrete” is the Latin verb “discernere,” meaning “to separate, distinguish,” from “dis,” apart, plus “cernere,” to separate. (“Discernere” is also the root of our modern English word “discern.”)
"discretion. If you have the freedom to decide something on your own, the decision is left to your discretion. You're in charge. Discretion traces back to the Latin verb discernere "to separate, to discern" from the prefix dis- "off, away" plus cernere "separate, sift."
So both words come from the same root!