Why middle names?

Why is it so important to many of you, to have a middle name. I mean... Some of you have the name picked out already but need help with a middle name and I'm not sure why it's necessary? Why not just go with a first and last name? I'm just curious why it is so important because I would only give a middle name if I had something I felt I needed to pass on 😊 No hard feelings, I'm just trying to understand you 😊