> If all you've seen is succesful projects, you can only guess why failed ones fail.

True. The project I have been a part of do have problems though. Sometimes the problems get resolved quickly and sometimes it takes a while or never happens.

Failure comes in many forms. I'm not pretending to have encyclopedic knowledge over the various ways projects fail. I do know that issues arise on the team and good communication often helps resolve these issues.

Also, having a good attitude is important. It's easy to be negative to your teammates (I have this problem), but it's also harmful and inappropriate at times.

In my experience, the biggest issues (or the largest cause of my stress) were often issues within the team.