Good idea for a poll. Minimising mistakes can be just as important as knowing what to do correctly. I see avoiding mistakes as playing good defence in the game of wealth creation.
From my own experience, the mistakes that afflicted me most initially were:
1. Unwillingness to have "a go": I could start a separate thread (perhaps I will some day!) on the opportunities I missed in not starting earlier. This is perhaps the most critical mistake of all, because as the cliché goes, if you don't have a go, the failure rate is 100%.
2. Fear: Knowledge, research came help to overcome this, because it often stems from the fear of the unknown, the "what ifs". Jan Somers has an excellent section in her books on dealing with "what ifs". The best “what if” of all is “what if you don’t?” (see above paragraph). If the answer to that question scares you, then your fear can be used positively.
Courage is not the absence of fear, but the mastery of it. Borrowing a lot of money for the first time is often intimidating, as I can attest. Once you do it, and find that the sky hasn’t fallen in, you start to wonder why you worried so much in the first place.
Once you decide to make the step to invest, then the other mistakes can kick in (all of which I hope to avoid making):
3. Being impatient/expecting too much: I see these as interwined. Many expect results without hard work, then give up. Wealth building is a long-term game.
4. Not thinking things through properly/not doing any research: Again these are connected.
5. Laziness: Wealth creation is not a “set and forget” process. You don’t get wealthy by doing little.
I’ve covered all the choices in the poll so you can guess I selected “All of the above”!
Here are some other mistakes I’ve thought of:
1. Not learning from previous mistakes: Mistakes are inevitable, but repetitions of past mistakes need not be.
2. Over-confidence: This can manifest itself in thinking you know everything, ignoring everyone's counsel (even that of other investors), selective ignorance (only absorbing views that concur with your own), not being prepared to observe and learn from the mistakes/experiences of others.
3. Not knowing yourself: How will you respond if things get tough? Will you run for the hills/make rash decisions if things temporarily move against you?
4. No buffers/fall-back: This applies not just to borrowing. See this thread on the dangers of your buffer running dry:
http://www.somersoft.com/forums/showthread.php?t=23497