@mincemeat,
First crushes last a long time, it's a great memory and it sounds as if you are starting to realise exactly that, " a great memory" but not for you.
You mention your "ex-friend" who he liked at that time.
My guess is that as a guy you thought was "ok" gave attention to your "then" friend, you wanted it for yourself as you saw it first hand, given she was your friend.
I'd also guess that as she isn't your friend anymore and as time has past and you are more mature you realise it for what it was, just a crush because she had his attention and you wanted "some attention" at that time.
I am sure you will meet an amazing person as well that you will have more than a crush on.