Student or Learner
HI, I KNOW WHAT "WATER UNDER THE BRIDGE" IS, BUT WHAT DOES IT REFER TO WHEN YOU SAY "TOO MUCH WATER UNDER THE BRIDGE"
This is an informal phrase that means too much has happened in the past about the situation, too many experiences, or that there is a history that one can refer to. The water that has alrady flowed under a bridge is a metaphor for things that have happened.
Mary said that John apologized but she added that too much water has gone under the bridge and she won't go back with him.