I did my engineering,then worked for 1 year,then did MBA and thereafter have been working for the last 3 years.While 4 years of total work-ex may not make me an authority on the subject,nevertheless I have these observations
When you pass out of graduate college(be it T-School,BCom,etc) and go into your 1st job,you tend to go with a lot of idealism(read - over expectations).One of the best things the 1st job does is crush a huge chunk of that.Not in the sense that you pay bribes etc after that,but you realise the importance of soft skills in any assignment,which a textbookish approach to problems will not teach you.You realise that you cannot attain success by applying set formulas for everything,unless you can carry your team-mates along with you regarding your ideas,solutions etc.You realise that success is not a matter of instant gratification;initiatives will take their cycle time to get implemented and unforeseen roadblocks will be there.
This learning is of great use during your MBA where the theoretical concepts can be internalised much more easily.And your expectations in your post MBA job will be much more realistic