What is loneliness people speak of? I am alone and I don't feel like I am missing out on anything. I am happy and content. I have fun. I am fine just entertaini

What is loneliness people speak of? I am alone and I don't feel like I am missing out on anything. I am happy and content. I have fun. I am fine just entertaining myself or going out to do things. I'd say I am by myself 95% of the time of every day. Is loneliness related to depression?