Fun Times

Fun.... what's that really mean? It is defined in so many ways. Is it something you enjoyed? or something that isn't real? a feeling, or an idea. I'll never know it's truth. Someone's perception of fun could be different than mine. So how can we truly define the word Fun times are great, Fun times are good, But how should we know what it really is? Yours and mine are different, Mine and yours are different. Is fun an opinion, Or a feeling? I would love to know it's origin, but sadly that won't do. I'm afraid if I know, "fun" won't mean the same it used to.