what's the mean of "pandora's box"?

[august1987]

what's the mean of "pandora's box"?Can you help me?
Thank you very much!

[Tdol]

All the evils of the world were in a box, which Pandora opened, releasing them into the world, so when doing something causes all sorts of problems, it is opening Pandora's box.

[nyggus]

All the evils of the world were in a box, which Pandora opened, releasing them into the world, so when doing something causes all sorts of problems, it is opening Pandora's box.

For instance: I started to learn English five years ago: it caused Pandora's box opened. I had no time for anything else than studying, so my wife left me, my uncle called me a liar, his wife said she was not his wife any more, the brother of my wife's brother kicked me in my the left knee and took off with all my money, and, finally, my brother said he didn't like English at all so I had to leave his apartment, in which my wife and I lived.
(Ok, I am just kidding: my wife haven't left me and I don't have a brother. Besides, no Pandora's box opened when I started to learn English, at least because of this reason.)
Best,
Nyggus
(Tdol: I would be grateful for editing this text. Thanks in advance.)

[Tdol]

it caused Pandora's box opened- I'd say 'this opened (a) Pandora's box'
anything else than- anything other than
my the left knee- my left knee

Just goes to show how hard studying a language can be.