Fumble!

While playing snooker the other night and missing some shots, this expletive from my university days came back to me.

It's easiest to explain by example so here are some:

After the exam:

A: What value for the inductance did you get for question 6?
B: 16.2 millihenry.
C: 16.2.
A: Aiyah! Fumble!

Missing the bus:

We stopped to chat and missed the last shuttle bus to the residential college and had to walk. Fumble!

Why so shy?

Why you didn't ask her out when you had a moment alone with her? Fumble, man!

Obviously it can be applied to situations where another expletive starting with fu might be used, but it also carries the implication that you are the author of your own misfortune, rather than blaming it on the universe.