I think it's very common. In most cases, you will feel like you learn more your first year out of school than you did in 4 years of school. I'm not sure that's really true though because what you don't realize is how much you've really learned in school.
What you do learn that first year or so is how to practically apply what you've learned.
A few other things you learn that first year:
1. In a general practice, 90% of the sick patients will get better on their own. The key is to not screw that up and to reassure the client. The other key is to pick out the 10% that have a truly serious problem.
(This rule doesn't apply for emergency practices. But a new graduate has no business working emergency alone, IMO. It also doesn't apply to referral practice, but new graduates working there are typically interns and therefore usually adequately supervised.)
2. Also in a general practice, 90% of the patients have 10% of the diseases. In other words, you spend most of your time managing the same things over and over.
3. Mentorship is key. These days I think very few new graduates are ready to practice on their own. Sure they can do it, but they won't do it well. The most important thing about your first job is to work with one or more good veterinarians who will take the time to mentor you. In general, you will start to practice like the other vets. If they're good, you will be too.
On the other hand, I've seen some very good students start in a lousy practice and pick up a lot of bad habits.
4. First impressions are important. The client doesn't know you, you're inexperienced, probably young, and you look it. If you look and act like a doctor (in other words what the client expects a doctor looks like) it will be much easier to get the client to trust you. Once you're established and the clients all know how good you are, you can dress however you want. But not when you're the new doc.
5. Compassion is every much as important as competence. The reality is most clients don't have a clue as to how good a veterinarian is at the technical aspects of diagnosis and treatment. Unless all your patients are dying, which shouldn't happen (see 1), clients judge you based on things like how well you seem to care about them and their animal. Take the time to really listen to their concerns. Return their phone calls and emails promptly. And never, ever loose your temper with their animal.
No matter how much they try to kill you.
I think being a new grad must just be a really steep learning curve and presumably I'll get there- but I find it alarming how much of what I've learnt I seem to have forgotten 
