True story: A woman interviewed for a job with a pretty great company. She was well qualified, said all the right things, and presented herself with her best foot forward. In the end, she was perfect for the job...but there was just something missing.
What was it? The warm-fuzzies, the butterflies, the "this feels great" kind of flutters you get when you meet someone you want to welcome into your life. It's like dating (yes, I said it). You might go out with someone who fits all the criteria on your list, the conversation can be right on target and the food can be great—but if the chemistry isn't there, you kindly part ways and start looking for the next best fit.
This experience can happen in job interviews, too. Not only can it happen, but it does happen. Fortunately, well-trained interviewers will put aside any personal lack of interest to consider how well a candidate would fit in with department members they'd be working with on a daily basis. Because it's a proven fact that employees who enjoy their coworkers are more likely to enjoy their job and look forward to going to work every day.
Unfortunately, this "interview chemistry" concept is completely subjective. But whatever quality caused one interviewer to fail to make a connection with you may be the same quality that makes the next one adore you. However it turns out, remember to not take it personally. Keep searching and if it doesn't work out, consider it good practice for the interview that'll get you your next job!