When I read the thread title I guessed the OP immediately.

In my experience, the closer you look at a friendship, the less you know how close it really is. Normally the question does not raise itself at all. In surprising circumstances, however, we may ask ourselves whom to trust and to ask for a really great favour. I am not sure at all which of my friendships would stand that test - "a friend in need" -, and I would be very happy never to find out. Not that I have never been in need of a favour, just not badly enough to safely distinguish between a friendly person and "a friend indeed".

Each friendship is as unique as the persons involved. Often we cannot say which one is closer than the other; in every pairing we share different experiences and different topics in which we understand one another closely.

The secret of a good friendship is that either partner takes a genuine interest in the true personality of the other. A pact for mutual help may be included, but it is a different thing.

Spaw: yes. Here's to him! I only exchanged a couple of bytes with him, so he must almost count as an "imaginary friend" of mine, but may he live in our hearts!