for the life of me

for the life of (one)

Despite one's best efforts; to any degree whatsoever. Often used in negative constructions. For the life of me, I can't remember where I left my keys! She couldn't understand for the life of her why people were so obsessed with celebrity gossip.
See also: life, of
Farlex Dictionary of Idioms.

for the life of me

at all; even one little bit. (Used with a negative.) For the life of me, I can't figure this out. I can't for the life of me climb up a mountain.
See also: life, of
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

for the life of me

however hard I try; even if my life depended on it. informal
1998 Robert Newman Manners I cannot for the life of me think what the name of the lead singer was.
See also: life, of
Farlex Partner Idioms Dictionary

for the life of me

I cannot/could not do something even to save my own life. The expression dates at least from the early eighteenth century and is generally used hyperbolically, that is, one’s life is not actually at stake. An early version appeared in Oliver Goldsmith’s The Vicar of Wakefield (1766): “Nor could I for my life see how the creation of the world had anything to do with what I was talking about.”
See also: life, of
The Dictionary of Clichés by Christine Ammer
See also:
  • mean (something) by (something)
  • mean by
  • change (one's) stripes
  • change one's stripes
  • change one's stripes/spots, cannot
  • a month of Sundays
  • take it with (one) (when one goes)
  • take it with one
  • anytime soon
  • have it both ways