1.      Assuming that you know everything

2.      Forgetting to network

3.      Not being prepared for meetings

4.      Ignoring the value of business cards

5.      Engaging in office drama

6.      Arriving to meetings late

7.      Not asking for more work when you’re bored

8.      Being satisfied doing the minimum amount of work necessary

9.      Not sharing your career goals with your leader

10.  Not reading up on your industry

11.  Forgetting to make a LinkedIn page

12.  Over-sharing personal stories at work

13.  Burning bridges when leaving a job

14.  Dressing unprofessionally

15.  Not proof-reading your e-mails

16.  Believing that you’re going to be a VP right out of college

17.  Not seeing the value in entry-level positions

18.  Not learning from your mistakes and failures

19.  Failing to seek out a mentor

20.  Thinking that once you choose a job field, you’re stuck with it forever

21.  Not having an updated resume available at all times

22.  Failing to join associations and groups pertaining to your industry

23.  Being a negative person

24.  Not taking initiative and turning down all new projects

25.  Forgetting to thank people who help you

26.  Not asking for help when you need it

27.  Failing to admit that you’re overwhelmed with your workload

28.  Trying to convince yourself that you love your job when you don’t

29.  Overestimating your abilities and not being honest about them

30.  Turning down training courses

31.  Not keeping track of all your accomplishments

32.  Making career decisions for anyone other than yourself

33.  Not actively looking for a job when you’re not happy with the one you have

34.  Thinking that it’s too late in life to change careers

35.  Making premature judgements of others

36.  Over-promising results, and then failing to deliver

37.  Not having a system for managing e-mails

38.  Failing to understand when and how you’re most productive

39.  Assuming that everyone around you thinks the same way you do

40.  Failing to accept diversity as an asset to your team

41.  Not caring how your actions affect other people

42.  Having an emotional IQ of zero

43.  Being scared to ask questions

44.  Making decisions that impact others without consulting with them first

45.  Believing that you need to be an a-hole to be taken seriously

46.  Taking jobs just for the money

47.  Not sharing your knowledge with others

48.  Letting your ego guide your decisions

49.  Not thinking big-picture

50.  Complaining about problems instead of offering solutions

51.  Failing to embrace change

52.  Being intimidated by new technology

53.  Not pushing yourself outside of your comfort zone

54.  Not giving yourself time to re-charge

55.  Not standing up for what you’re worth