I agree with LT, Kit, that sometimes you just have a feeling that you can trust someone. I trusted L very early on, within a few sessions iirc - told her something that happened to me when I was a kid that I'd never spoken a word of to another soul (and still haven't) pretty early on in our first year. I still remember sitting there on the couch in her old office saying it and she witnessed it quietly. I'm not sure how I knew I could trust her I just knew I could and did.