For the sketch provided with this lesson, I had to set node-red ui_switch on value to “1” rather than the “On” value given in the course text. Also set “Off” value to “0”. When configured as described in lesson built in led would light on boot and switch in node-red-ui indicated On, moving switch to Off switched led off, but even though switch activity was logged “On” or “Off” in serial output stream led would not switch back on again until reboot. I would like to understand where this difference in terms comes into effect. Is it in the Arduino compiler, the ESP8266 firmware, the node-red script, or the mqtt server? Can these terms (On for True, Off for False, etc.) be flexible or interchangeable? Must they match across the whole process from source code to the transistor that turns the pin on or off? I really want to learn coding but little frustrating glitches like this make me realize how much there is to learn. Discouragement often results from a lack of understanding simple details usually taken for granted.