Q1: get a life = try to make a good life for yourself?Let me assure him, here in the real world <cite>no one, </cite>but no one, is saying: 'What we want is David Miliband.' Most people have no idea who he is, otherwise they would pelt him with rotten food from their overflowing dustbins every time he dared show his face in public.
So give it a rest, old son. Get a life.
Q2: old son = my familiar young man?
My mum watches soap operas all the time and calls me five times a day.
Oh, she should get a life!
- means: she should do sth to improve her situation, change her lifestyle for the better, for example make some friends, start a hobby, so she can think about her own life not the lifes of soap opera characters or her children.
Tom and Anna split up and now Tom sits at home and cries all the time.
He should give it a rest (forget about Ann) and get a life!
Thank you for the answers of you two. The penny dropped.