Your corn is sweeter, your potatoes are starchier and your turkey is much, much bigger than the foods that sat on your grandparents' Thanksgiving dinner table.
Most everything on your plate has undergone tremendous genetic change under the intense selective pressures of industrial farming. Pilgrims and American Indians ate foods called corn and turkey, but the actual organisms they consumed didn't look or taste much at all like our modern variants do.
In fact, just about every crop and animal that humans eat has experienced some consequential change in its DNA, but human expectations have changed right along with them. Thus, even though corn might be sweeter now, modern people don't necessarily savor it any more than their ancestors did.