過ぎたことを振り返ってはいけない。

to pass through; to pass by; to go beyond; to pass (i.e. of time); to elapse; to have expired; to have ended; to be over; to exceed; to surpass; to be above; to be no more than ...; to be excessive; to be too much; to be too ...

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to turn head; to look over one's shoulder; to turn around; to look back; to think back (on); to reminisce; to look back (on); to reflect (on)

if ... then; when; and; why don't you...?; the more (one does something); because; since