I know I thought about it before leaving!!!!!!!
The Maastricht pension, once you qualify, is payable anywhere in the world. Most expats work under a gratuity-type system (Hong Kong, middle east etc.).
And if you think the superannuation/pension rules will be the same, anywhere, in the future, you are dreaming. My advice is to look after yourself, and if you get anything from any government/employer anywhere, treat it as a bonus. One of the lures for expats is the ability to do just that.