Some "weak" habits I've seen in young entrepreneurs include (1) building the product before they know the demand for it, so it goes nowhere and they get disheartened easily. Test the idea/service/product on your target market and hear their feedback to refine your offering (2) taking "negative" feedback personally rather than seeing the GREAT INSIGHT they're receiving into the markets problem and potential obstacles/barriers to them buying. Turn the feedback around into great market research instead. (3) underestimating the strengths they personally and professionally have, while simultaneously keeping an open mind at how something can be done better or more effectively. It's a personal self image and skill set balance to strike. Overall I equate being an entrepreneur as having a flexible, nimble mindset while staying focused on your vision and outcomes. Note, focused doesn't mean "fixed" mindset! Know the WHAT and be open to the HOW....It's an adventure everyday!