It's almost always the case that the higher the level of joyful anticipation, the bigger the let down. Christmas is a regular feature in this department but there are lots of other examples. An Ian Brown concert, for instance. Or a Gordon Brown Premiership.
And what about bird watching? You look at some of the books on bird spotting and become quite enthusiastic about giving it a try, eager to sample the colourful delights of Darwinian diversity in the airborn branches of creation.
This is the sight that befell us when we trudged down to the Nature Reserve on the first day of our holiday and I think it aptly demonstrates the vast chasm between expectation and practise.