So what can you do? With prompting from alumni, many business schools are taking the current impetus for continuous lifelong development to heart, and providing various ways in which MBAs can update their management skills and prolong their exposure to new ideas and ways of working.
Bath, for instance, has established a new programme, Management for the 21st Century. The series of one-day events programmes is designed with busy executives in mind. Running once a month from February, the school's leading academics will cover six topics: long-term planning; strategic options analysis; business networks; leadership; management of innovation, and risk management - with a practical programme based on case studies and syndicate team sessions.
"We perceived the need for ex-MBAs who graduated up to three years ago to come back and get the latest thinking, based on the latest research," says David Groves, executive development manager at the University of Bath School of Management.
"Thinking changes and goes through fads and phases as business gurus pick up things such as re-engineering, and we're all likely to forget some of the lessons we learned during our MBA. People wonder what they're missing out on when they haven't got time to read. Most people see their MBA as a long-term investment and look to their business school to provide an after-care service and help them to update."
Mr Groves hopes that people will pay for a season ticket to all six sessions - at a cost of pounds 1,800 compared with pounds 350 individually. "Hopefully they will form a group that becomes self-perpetuating," he says. "They can then come up with subjects themselves that they would like us to do."
When it comes to lifelong learning, Westminster Business School has also seen the writing on the wall. While it has always welcomed its MBA graduates to pick and choose modules from its range of masters courses - if, for instance, someone moves into a new job area or wants to revisit an elective in more depth - in the new year it will be starting a series of monthly "lunchbox" sessions aimed at its MBA alumni.
"We've been talking about doing it for some time," says Carol Blackman, director of external relations at Westminster Business School. "Our students say they feel the need to update, especially as their organisations become more concerned about this, and we were actually approached by our MBA alumni to organise something."
Free to alumni for the first year, the format of the "lunchbox" initiative will be simple - sandwiches and a speaker, who will give a 20- to 30-minute presentation on some aspect of management, followed by a chance for discussion. The topics will be quite specific: decentralisation; budget management; cross-cultural management; mentoring; leadership.
Beginning next year, Westminster is also planning to run occasional weekend sessions covering more of the tools and technology of management, such as scenario planning and modelling, and personnel issues such as team building and risk management. "We will probably run three a year, but if we get an overwhelming response we could run them more frequently," says Ms Blackman. "Basically we're testing the water to see how much MBAs do want to update themselves. They frequently say at the end of their course that they really want to keep up to date, but quite often that enthusiasm wears off once they get back into their job."
However, while keeping up to speed is a matter of professional pride, the benefits of a refresher don't just stop at new ideas. "Particularly if your company does not have a lot of MBA graduates, you can miss the challenge of talking to some people who have similar interest in management approaches," says Ms Blackman. "It's the networking effect which will be so important on this refresher. It renews that chance to talk to other people in the same field, or in a different field but facing similar problems, and you get to see different ways of tackling things."
Cranfield is already two years down the line with refreshers for MBAs. Its autumn weekend, run by Cranfield Alumni Lifetime Learning (Call), is now an annual event; it was over-subscribed last year to the tune of 160 applications for 110 places. Some of those who attend did their MBA as far back as 1965.
"What we want to do is add value for our alumni," says Caroline Smith, director of Call. "One subject that is very live at the moment is offering lifetime learning activities. We realised this is a major area and that people are very interested in updating their MBA."
The plenary sessions are run by the pick of Cranfield's faculty, and there's a choice of 15 workshops over the two days, covering topics such as innovation management, high performing teams, risk management, career crafting, leading change and coaching and mentoring.
"Our new professor of international strategy did a session on strategic acquisitions, and we had a session on key account management," says Ms Smith. "Basically we ask them to do something that the alumni won't have heard about much before.
"The aim is to give a taste of what's around, an opportunity to see what you might be looking into more. The idea is that if it hooks their interest they can then pick up and run with it and get further information."
Call doesn't intend to stop there, however. While looking into one-day conferences, a mentoring scheme and study tours, it also wants to develop the potential of the Internet to help its alumni update. "We had some virtual workshops in the weeks preceding and following the event on the web so people could receive lectures on the subject of creativity," says Ms Smith. "I think this will be an important way of updating in the future."Reuse content