Let’s start this topic with an exercise. If you are not already on one, move to sit on a straight-backed chair,

like one at a desk or at a dining table. Done? OK, now while sitting here, think about the taste of a banana . . . . . . now think about the feel of leather . . . . . . multiply 17 by 17 . . . . . . and see if you can remember the tune, ‘The Yellow Submarine’. Next, while sitting on the chair, put this book in your lap, or if you are

sitting in front of a table, place it on the table. Ready? Now carry on . . . Drop your hands and take hold of either side of your seat and using all

your strength, pull up, and also push your feet down into the floor. While doing this think of the tune, ‘The Yellow Submarine’ . . .