Why is it important to "rest" meats before cutting into them?

Meats are basically water, protein and fat. When you cook meats, you end up breaking those long protein chains. If you cut into the meat it will lose water because those chains aren't there to keep water in.

If you wait and let the meat cool, these protein chains start to combine back together. Cutting into it now releases less water so your meat is jucier.

Proteins thicken the juices as it's rested so the juices don't flow out of the meat when it's cut. The taste will be better.

Because it lets the juices incorporate into the meat. If you don't let it rest, then the juice ends up on the plate making the meat dry.

It's supposed to give the meat time to reabsorb the juices that it lost while cooking. People like juicy meat.

It's supposed to let the juices "redistribute". May be so, but I'd like my meat HOT, please, not sitting around somewhere getting cold for 10 minutes.

That's something I've wondered all my life, too. It's a common thing for my mom to say after taking a turkey, chicken, or roast beef out of the oven. Even steaks brought in from the grill, she says to let the meat "rest". But I've never heard any reasoning behind it, at least nothing that made sense. If you looked in an older cookbook it might give some reasoning for "resting" the meat before cutting, but I'd bet money that with a side by side comparison between meat that was rested before cutting and meat that was not rested before cutting, nobody could tell any difference in taste or texture.

Here's what I found with a quick google search:

"If given the time to rest the meat will lose less juice when you cut it and when you eat it the meat will be juicier and tastier. The time taken to rest will depend on its size, a roast is best rested for 10 to 20 minutes before carving. Steaks or chops should stand for 5 minutes (but no less than 3) before serving."

Once again, I bet nobody could tell the difference between rested and non-rested meat. And if a roast sits for 10 to 20 minutes before carving, it won't be very hot any more.