I'm having a postdoc interview coming up, which is not in my doctoral topic or not so closely related to my previous postdoc research. While applying for it, I thought I'd not called for an interview, but luckily enough, I did. The reason I didn't think I'd get called for an interview, as I can see that I'd need learn quite a few things that'd take me easily a minimum of three months to get the hang of.
So will it be rude to ask my interviewer her/his motivation to interview me or what (s)he thinks I can do for her/him, or if not, then what's the best way to formulate my question, without sounding like I'm trying to hear some good words about myself from the interviewer? I guess one of the option might be "What part of my backgrounds can be useful to your project?" but I'm looking for a sincere, honest and a genuine reformulation of this. I'm interested in the project but my concern is it might take me at least 3 months to get myself up to speed to start to solve the problems.