A haiku poem that uses a fortuitous numerical fact about a birthday probability that can launch discussion of the "68-95-99.7 rule" and how 99.73% of values are within 3 standard deviations of the mean for a normal distribution. Here 364/365 ≈ 0.9973 (365/366 is the same out to four decimals so this also applies to leap years). Students can also recognize that birthdays do not follow a normal distribution, but approximately a uniform distribution (so that the approximate chance that two people have different birthdays is about .9973) . The poem was written by Lawrence Lesser from The University of Texas at El Paso in February, 2021.