丢在脑袋后头
diū​zài​nǎo​dai​hòu​tou

to forget about

  1. 丢 丟 diū
    to put aside
    to put aside or shelve; to stop practicing a skill for a long time
  2. 在 zài
    [location/time]
    Used as a linker to introduce the time, place, or situation of an action, meaning "at", "in", or "on".
  3. 脑袋 腦袋 nǎo​dai
    head
    (colloquial) head of a person or animal; skull
  4. 后头 後頭 hòu​tou
    back
    the rear; the back; the space behind something