Lost it in the war
When you suddenly forget about the topic, the flash of memory erase making you loose that "thing" in the war!!
Aaron: What was the name of that noob on cs?
Jim: Umm... Fuck! Lost it in the war!!
Aaron: Oh noes!! I want to troll his next server!!
Jim: Umm... Fuck! Lost it in the war!!
Aaron: Oh noes!! I want to troll his next server!!
Won the battle, lost the war
When one is so concentrated into completing a task that he/she thought was so big, but at the end realized it was nothing compared to the big picture that he/she lost.
I've passed my exam, but lost a gf. I've won the battle, lost the war.