Life looks very simple with a brand new MBA degree and a cool job in the bag. Ah, if only it was that simple!

The difference between doing well at B-school and being a good, effective manager is the difference between simulation and reality. What B-school taught me was just the beginning, experience has taught me much more.

One of the most important lessons is to say "no". As human beings, our behaviour is shaped by the need to create and maintain relationships. We want people around us to like us and accept us. But at times, you have to act in a way that is not acceptable to the other person.

It may be a friend with whom you also happen to be doing business, an employee or a colleague making an unreasonable demand, or a large unprofitable business opportunity.

In such situations you needs to be clear and firm. It may be difficult to say no, but it has to be done. It's impossible to sustain a relationship if each party does not respect the concerns of the other.

Most management graduates tend to focus only on their strengths and land up ignoring their weaknesses. Managers are generalists, not specialists. Often, they have to carry out many functions for which they are not completely trained.

The only way they can adapt and be effective is to be clear about their areas of weaknesses, work on them and gradually improve.

For instance, most MBAs ignore organisational behaviour and human resources in their curriculum, but in real life these two areas comprise about 80 per cent of management time.

And finally, business is all about risk. Therefore, even though you may make mistakes, it is far better to take decisions when you need to, than not take any at all. It's better for managers to take 10 decisions and get seven of them right, rather than procrastinate and not take any decisions at all.