Water under the bridge implies that something that has already happened cannot be changed. The water that has gone under the bridge is not going to come back, it is gone. An event that has taken place cannot be changed so there is no point in speculating about it.

A hungry wolf tries to put down as much food as possible in a short time. The term implies that the speaker is really very hungry. A person “wolfing down his food” is stuffing food quickly into his mouth.” However, the “in heat” part is a puzzle to me. I have never heard it said that way. Maybe someone else has an answer to that one.

That’s water under the bridge – Nothing you can do about it anymore.

I’m hungrier than a ***** wolf in heat. – Its either you’re hungry or you’re really horny.

water under the bridge, if the water has flown under it is gone no way to stop it, hence water under the bridge is a problem u cant do anything about because it is past, just have to live with it

the last one is just a metaphor for hungry as a bear etc

just means u r hungry

That’s water under the bridge. – you’re are over something

I’m hungrier than a ***** wolf in heat.-idk abou this one