"I should be so lucky"

What does "I should be so lucky" mean ? Could you please give me examples of situation when you could use this phrase. Thanks.

My next door neighbor just won a million dollars in Lotto.
I should be so lucky.

Can also be rueful or sardonic, ir express chagrin. "Hey, you look different. Did you lose some weight?" "I should be so lucky!" Or: "I haven't seen your ex-wife lately. Did she leave town?" "I should be so lucky." Or: "Was that you I saw out with that hot new chick from the office?" "I should be so lucky." Or: "Hey, you look pretty gloomy. In fact, you look as though you had recently died." "I should be so lucky."

The expression means, more or less sarcastically: "As though I could be that lucky! But obviously I can't."

It's an example of Jewish humor, brought to American English by Yiddish-speaking immigrants, along with "Who needs it?" and "Like a hole in the head."