She held the car grimly to the road as it negotiated the bends with considerable difficulty and the straight sections with only slightly less. The ca… - Douglas Adams

It is of course perfectly natural to assume that everyone else is having a far more exciting time than you. Human beings, for instance, have a phrase that describes this phenomenon, ‘The other man’s grass is always greener.’
The Shaltanac race of Broopkidren 13 had a similar phrase, but since their planet is somewhat eccentric, botanically speaking, the best they could manage was, ‘The other Shaltanac's joopleberry shrub is always a more mauvy shade of pinky-russet.’ And so the expression soon fell into disuse, and the Shaltanacs had little option but to become terribly happy and contented with their lot, much to the surprise of everyone else in the Galaxy who had not realized that the best way not to be unhappy is not to have a word for it.

One is never alone with a rubber duck.

"Ghastly," continued Marvin, "it all is. Absolutely ghastly. Just don't even talk about it. Look at this door," he said, stepping through it. The irony circuits cut in to his voice modulator as he mimicked the style of the sales brochure. " 'All the doors in his spaceship have a cheerful and sunny disposition. It is their pleasure to open for you, and their satisfaction to close again with the knowledge of a job well done.' "
As the door closed behind them it became apparent that it did indeed have a satisfied sighlike quality to it. "Hummmmmmmyummmmmmmah!" it said.