30 Is a Dangerous Age, Cynthia! (1968)

If you haven't made it by the time you're 30, you never will....ask anybody!

A 29-year old aspiring composer—still single and without any romantic prospects—vows to both marry and write a hit musical before he turns 30. Director Joseph McGrath's 1968 British comedy stars Dudley Moore, Suzy Kendall, Eddie Foy Jr. and Patricia Routledge.