TorschlusspanikThis is high up on my list of frequently-felt emotions, a little behind schadenfreude and buyer's remorse, and perhaps slightly ahead of envy. Also provides an excuse to quote Auden:
From German, this word literally means “gate-closing panic” and is used to describe the fear of diminishing opportunities as one ages. This word is most frequently applied to women who race the “biological clock” to wed and bear children.
Certain it became while we were still incomplete
There were certain prizes for which we would never compete:
A choice was killed by every childish illness,
The boiling tears among the hothouse plants,
The rigid promise fractured in the garden,
And the long aunts.
And every day there bolted from the field
Desires to which we could not yield;
Fewer and clearer grew the plans,
Schemes for a life and sketches for a hatred,
And early among my interesting scrawls
Appeared your portrait.
(Another worthwhile untranslatable is "tartle" -- "a Scottish verb meaning to hesitate while introducing someone due to having forgotten his/her name.")