lǎo pó shì bié rén de liàng
Your neighbour’s wife looks prettier than your own.
Or, as we would say ‘The grass is always greener on the other side of the fence’.
I know some people who are always comparing their lot in life unfavourably with that of others, and it is such a pointless exercise and extremely dispiriting to boot.
A London friend always amuses me when we eat at a restaurant together. Everyone peruses the menu, ums and ahs about what to order and then makes a decision. When the food arrives, this particular friend looks round at what everyone else has on their plates and a barely disguised look of irritation crosses his face as he decides our choices look better than his…he then offers to swap plates with anyone who “doesn’t like what they’ve ordered” when the truth is that the only one who is discontent is himself, and usually his food is delicious anyway.