Frequently they are.
Denis McBrinn of Protocol Skills, the lecturer-supply agency, clearly took this into account when he spoke at a conference organised by Ulster's Learning and Skills Development Agency last week.
He recounted how a professor used props for a Tommy Cooper-style demonstration to underline the importance of basic skills (or essential skills as they are known in the province).
The professor filled a glass with golf balls and asked his students if it was full. Yes, they said (you can't get the talent in HE). Then he poured some small pebbles in to fill the spaces, and asked the same question. Yes, it's definitely full now, they said.
Then he filled the remaining gaps by pouring some sand in. OK, they said, now it is full. Then, with a flourish, he produced two glasses of beer. He poured the liquid into the glass and the students watched as it was soaked up by the contents.
He told them the golf balls represent the important things in life - such as basic skills (or golf), the pebbles stood for the less-important stuff, such as the car and the career. And the sand? That was for the trivial stuff which we like to have in our lives but isn't that important.
He explained that the moral of the demonstration was that if you fill you life up with trivial stuff, there's no room left for the really important things such as basic skills (and golf).
"But why did you add the beer?" asked one student.
"That," explained the professor, "is to show that, however full your life is, there's always room for a couple of beers."