Your Friends Are Not in Your Phone

When I was a freshman in college, I frequently found myself in the worst kind of conversation possible, or so it seemed to me at the time. Say you have a cow. Say you cut off part of the cow. Is it still a cow? Why is it the case that pudding is still pudding no matter how much pudding there is left, and the same is true for milk and any kind of oil, but then also, that the cow seems different?