Known generically as an "orchid cactus", an epiphyllum was the first plant I acquired for myself in college.
I went to a yard sale, and the gentleman selling it (erroneously) said "It's a night-blooming cereus that just bloomed. It only blooms every seven years, so it's got to go." It was a large, weird-looking plant in a 10" pot for 50 cents, so home it came.
It bloomed that summer and periodically thereafter, but was another victim of the "big freeze" that wiped out my 20-year orchid collection in 1994.
Fast forward to this spring, and a Hawaiian grower on another forum posted a flower photo. I asked if he could send me a cutting, and about a week later, a single leaf arrived.
I half-filled a 4" pot with potting soil and jammed it in. It started growing a single stalk about 6 weeks later, and then the old leaf started forming a bud. I had no idea a plant this small could bloom!