Birthday and initial letters co-incidence

Arriving at Sussex University in 1969, I discovered that my room-mate shared the same birthday as I, viz. 15/8/51. This was a co-incidence as we were both meant to share with other people, who having arrived earlier at our desginated guest house, decided to share. My room-mate's initials were JAH, mine JWH. In the second year, we shared a flat with two girls who had shared a room in digs. Their birthday was 11/12/50, and their initials were JMH and GMH. We accordingly had two birhtdays between us and 6 initials out of a possible total of 12. Both JWH and JMH were known by their middle names. When GMH went abroad for the third year, our new flatmate fulfilled the initials co-incidence, MJH, but, alas, not the birthday co-incidence. We remain friends over 40 years later.