Of I understand how you feel

Whenever you are complaining something to some other people, do you often hear back the phrase;

...Yeah, I can understand how you feel...
...I know exactly how you feel man...
...I feel you dude...

or something like that?

Cliche? It's more than cliche.
Personally, I don't think anyone can actually understand how other feels when they are going through something. Sure ... you can IMAGINE how it feels if you are going through the same thing, and THINK that's how you would react or feel if it happens to you. But, that's just your imagination. The closest you get is just ... IMAGINATION.
If everyone can just IMAGINE the kind of pain/devastation a person felt for something lost, everyone can be great inspired artist. Ok. I am over-generalizing. But you get the point.

Even when you do actually went through the same thing, I still think that it's hard to actually understand how the other person is reacting/feeling. Different people just have different attachment to the same situation. The most you actually feel is just what you do feel. Not the other party.

Saying "I understand how you feel" even when you are sincerely sympathetic can be very ... unsympathetic. Because ... you can understand what he/she is going through perhaps. But not exactly how they feel.

I need to hold back the urge to say I understand how you feel. Because after thinking about it, I really do think that it's rather hard to actually fully understand what the other party is feeling. Like I said, the closest I can get is to how I feel.

Which may be the same feeling they are going through.
But also maybe not.

And probably not.