How many times after a week writing endless essays and drawing up seamless plans that you know will be shredded by belligerent teenagers whose homework still has to be marked, have you dragged yourself to the nearest pub to hear the immortal words: "It can't be all bad. I wish I got those really long holidays".
The problem with extended time off - even ignoring those days spent catching up or just sleeping - is that they have to be taken at precisely the time that travel companies stack the charges: the school holidays.
Duncan Roberts, newly qualified, teaching geography and PE at Challenge high school Bradford, has particular reason to rue the high cost of holidays. When he proposed to his fiancee, Liz, he imagined honeymooning in Mexico or the Seychelles, but has had to settle for Greece.
"I had hoped for somewhere more exotic, but for two weeks in August, Zante was all we could afford," he says. "I knew it would be expensive, but I was surprised by how much prices rose: some went up from pound;800 one week to pound;1,400 the next."
Even so, he is not too bitter. "Some of my friends only get three weeks of leave a year. I think all the extra time I get does make up for the high cost."
Unfortunately for those with wanderlust, the experts can offer little to assuage the price pain. There appear to be two options: book very early or very late.
Jennifer Nicholas, proprietor of Riviera Travel in Burton on Trent, is an advocate of the former. "The only way to guarantee cheaper holidays, where you want to go is to book early before prices start to rise," she says.
"Take advantage of all the early-booker offers.
"You might get something if you wait for a late deal, but most operators are heavily over-subscribed. It depends on how strong your nerve is."
Ms Nicholas recommends Croatia and Bulgaria for cheaper peak holidays this year. Riveria can offer a Whitsun week break on the Bulgarian coast in the equivalent of a three- star hotel for pound;419 per person.
On the other side of the argument is Louise Gowling, of STA Travel, the company that specialises deals for under-26s. She believes that last-minute is the only way to find cheaper prices at peak times.
"It is very hard if you are married or have children, because you have to be very flexible to get the best late deals. There are always loads around if you are not bound to one date or destination," she says.
Kate Roe, who teaches at St Mary's primary school, Slough, west London, has nothing nearly so romantic or as expensive as a honeymoon planned.
"I know any trip will cost an awful lot of money," she says, "so I haven't planned anything at all for next year.
"All I need is a trip to see my mum. I get pampered more than enough there."
Riviera Travel: Riviera-travel.co.uk; 01453 82 83 84STA Travel: Statravel.co.uk; National Call Centre: 0870 1 600 599Expedia: Expedia.co.ukLonely Planet: Lonelyplanet.com