我怎么把她给忘了？
“How did I forget about her?”
THE DIALOGUE REEL
等等
“Wait.”
我 怎么 把她给忘了 ？
“How did I forget about her?”
烦人得很
“So annoying.”
“Darn it, of all people, how could I have slipped up and forgotten about her?”
Asking 'how could I' (我怎么...) is a frequent colloquial formula to express momentary lapse in memory mixed with self-blame.
LEARNING CHUNKS & PARTICLES
How on earth did I forget...
A very common colloquial pattern used to express self-rebuke upon realizing a sudden oversight.
VOCABULARY & EXPRESSIONS
Parallel Spoken Cinema Scenes (语义近邻切片)
“How could I forget him?”
“Why I keep looking for her is to ask her why she abandoned me.”
“How did I forget about the underground garage?”
“How could I have forgotten about you?”