One of the reasons the author agreed to teach a hybrid, on-line course last summer was specifically to either challenge or confirm her negative perceptions about on-line instruction. In order to continue to be an outspoken critic whenever administrators encouraged developing on-line courses for what she assumed were pecuniary considerations, she needed to understand on-line instruction from the inside out. The course, an elective in a Literacy masters' level program, was designed to introduce students to the range of materials available to teach K-6 language arts and to show them how to establish criteria in selecting and using such materials. The author is pleased to report that her experience in teaching this course confirmed her original perception; it was nothing like the instructional model she had been practicing for many years. What she could not predict based on her old schema was that effective on-line instruction is something brand new. In doing the research to prepare for the course, she began to realize that if she had tried to replicate the in-class formula, the course would have probably been as dismal as she feared it would be. The opportunity to review pedagogical issues that she had taken for granted through the years was the first of many unexpected benefits she encountered through this venture. The author became a proponent of on-line instruction. In this article, she shares 10 discoveries she made about on-line instruction that were beyond her field of vision when she viewed it through her in-class lens. The first four points reflect discoveries she made by reviewing the research before she taught the course and were reflected in the course design. The last six points reflect discoveries she made by assessing the course both during and after its implementation.