I assume you're asking if I had obtained the necessary skills from my schooling to perform my job when I first entered the workforce. I had most, but there were some that were very different from what I expected, and some prior mentoring would have been very valuable. Here are the high points:
1) School is a very individual-contributor-oriented environment. Much of the workplace in a technical field isn't. It is often a team effort, and interfaces to other people are critical.
2) Everyone at work is smart. At least at my jobs. The differentiator is often people skills or dedication and a willingness to do whatever is necessary.
3) You are not rewarded for being good at "reinventing the wheel". If you waste time coming up with a new way to do something that doesn't completely exceed known approaches, just go with the known approach and apply your efforts to solving an unsolved problem.
4) Going it alone may make you a stronger person, but it doesn't help the bottom line of the company much, so don't be afraid to ask for help.
Those are biggies.