Being pessimistic isn't quite the same as being unhappy, it's just that I've been a cormadgen , curmudgen - whatever! - long before I could spell the word. I've always been a believer in the Second Law of Thermodynamics which states that sooner or later everything turns to shit.
I am never happier than when complaining, so make me happy by not wishing me a happy birthday so I have something to complain about.
As Eeyore famously said, "Thanks for noticin' me."