Everyone has differing opinions when it comes to sharing food. Some people love to order dishes for the table, doing everything family style where everyone gets a little bit of everything. I’m totally for this when the time is right. If we’re at a dim sum restaurant with a Lazy Susan, there’s no other way to do it. Sharing is caring (as long as you make sure to order enough food). If we’re all getting soup, that might be a different story. Not many people love dipping their used spoon into liquid that has had many used spoons dipped into it. Each situation calls for a different level of sharing awareness.
If we’re at work, and I brought in leftovers of my roommate’s famous mac and cheese, which she only makes once a year, I don’t especially feel like forking over a bite to one of my coworkers. Maybe I’ll bring in extra cookies to the office from an especially large batch, but sharing lunch is pretty intimate.