Good Friday

I guess most people have forgotten what good friday is all about although I dont know much abbout it myself and tell you what last week thursday I watched the film about how jesus christ was crucified, didnt know much about it before until then, not that I dont go to church but because Bible is not that easy to read didnt find all about it but now that I know it am glad and I know the significance.
This morning when I woke up I inserted one of my favourites Nigerian gospel muisc and I started dancing but my Mum told me it's not such a good day for rejoicing, Do you really think so because I think because Jesus died hundred of years ago we should only remember and not to mourn or what do y'all think?
Another thing that surprises me is that my Mum said some church cries on Good friday becuase they thing its sad and that it's good to cry and laughed and couldn't believe it.