TIL: 3-way CFL bulb

I have a set of reading lamps, one everywhere we might sit and read, all with 3-way CFL bulbs. The lamp I use most often only had two settings: two clicks for OFF, two clicks for ON. Since I've had many 3-way incandescent bulbs before, I shrugged, and thought, "that's how it always goes: one filament burns out long before the other." I knew it was CFL, but I didn't put much thought into that because the "failure" mode was familiar. Tonight I decided to replace that bulb. And that's when I discovered it wasn't screwed in all the way. As soon as I screwed the original 3-way CFL bulb in all the way, it had four states again: HIGH, MEDIUM, LOW, and OFF. Now I wish I had checked sooner!