1we had almost given up hope when he pulled a rabbit out of the hat  by coming up with  a great new idea.

2you didn't know how the story would end and then the author pulled a rabbit out of the hat and it all made sense.

3 he has to made so many officical appearances that he seldom get a chance to let this hair down and enjoy life like ordinary people.

4 we have been good friends for a long time ,but lately i get the idea you are very much upset with me . i wish you'd let your hair down  and tell me what's wrong to make you fell this way