A lot of the time it takes you from 0 to 0.1, but (a) every little helps (b) if you take them out for lunch or a post-work beer or whatever it can build a relationship where you can ask follow up questions via email.

Ideal is if they have a life such that something morally equivalent to "how about we meet up and I'll pay for the food/beer" is a viable thing to suggest later.

Oh, and always remember - the way to a geek's schedule is often through their wife. If you get a chance to meet their partner, TAKE IT and be on your best behaviour, if $partner likes you then you have massively increased chances of making useful things happen later.

Yeah, that's a good point. But I think more often it's closer to 1 because (I guess this depends on our definition of 0 and 1 haha! :)) a) you get the benefit of their conceptual models for thinking about the codebase, which is hard won and highly useful, and b) you grok any practical pitfalls or things to remember when running, building, testing, that may be simple enough, but in the space of all possibilities are hard to come by without knowing them.

So basically you get to go from: 0 - can do nothing at all; to 1 - being able to feel confident diving in and looking around, framed with the downloaded conceptual models, knowing how to hit the ground trotting, if not running.

To me, 0.1 is more like you slugged it out for a couple hours poking around by yourself, and now you know a handful of confusing things with low confidence.

Chatting to one who has been there, done that lets you have more confidence, and know more actionable stuff, which is highly useful. I suppose it depends on your conversation, listening and comprehension skills tho! Hahaha! :)

But seriously not everybody learns well in that situation. I just happen to. I'd much rather talk it over with someone and absorb, than watch a video or read a tutorial.

Finally -- haha! :) -- I guess there are some geeks to whose schedule the way is through their husband or whatevs haha! :)