Why, sometimes I've believed as many as six impossible things before breakfast.
We meet this quite famous quote in the book “Through the Looking Glass and What Alice Found There” by Lewis Carroll. It is from Chapter 5 “Wool and Water”, Page 69. There the White Queen explains Alice that the things there are happening backwards. For example she first screams, then tries to fasten her brooch and pricks her finger. So all the screaming is over before the actual pain. When Alice says she can’t wrap her mind around such impossible things, the Queen pities her and tries to teach Alice to believe, asking her to relax, breeze deeply and think about it a bit harder. Alice still can’t manage it, but the Queen comforts her that it’s practicing that really matters. She says that she was training from her childhood and concludes with this quote, illustrating her impressive results in believing in the unbelievable.