1. That this job will pay you a lot more than you ever were paid before
2. That you did not like your previous boss or anyone else at previous jobs
3. That you do not have questions about the job
4. That you have personal or medical problems, e.g. divorces
5. That you are pregnant - none of their business. Though pregnancies should be celebrated, not every employer looks at that that way!
6. If you are overqualified - some time high qualification is a blessing for an interviewer, but again, many employers look at that this is a giant negative
And finally, that you never had that much responsibility as this position will offer you. "If anyone offers you an awesome opportunity but you haven’t made your mind to accept it, say yes – then learn how to do it later!” Richard Branson
If hiring manager is willing to take a chance on you, then they are unbiased and people-oriented.
I wish more employers took more chances on people like that.