The best mentors I've had have been people I didn't know were my mentors until I thought about it. A perhaps my experience would be 'People I met outside a cas

The best mentors I've had have been people I didn't know were my mentors until I thought about it. A perhaps my experience would be 'People I met outside a casual social circle (though I see no reason they can't exist within) with a high level of experience and insight into a field of expertise (technical or non-technical) that also enjoyed my company and my giving / reflecting something back to them.' Seek people out in environments you're comfortable, and don't discount the value-add face-to-face contact can make. A small word of warning also - mentors can be great inspirers, but that doesn't mean they would make a good fit as a boss or employee later (just as working _for_ a friend can break relationships).