My best friend is actually my oldest one... I mean, we've known each other for the longest period: we've been together since the first grade, than during highschool, and now we're in the same college... And even neighbours... We've grown up together, seen each other going through different phases, we know best how we react - even if we have different tastes and opinions, we have the same background, and we understand each other perfectly. So I completely trust my friend, just as much as I trust someone from my own family, as I consider my best friend part of my family... I think that pretty much says it all!