how can you say "THIS person is my best friend"??

I think this are one of these things that u don't have to wander about.... it's something u just feel and changes with time. For some people a best friends didin't exist, it's just a question of point of views and circumstances

When that somebody is there for you, to lean on, to dry your tears, to lend you a hug and support you, as you would be them. You would need to be able to trust them, rely on them at all times, be able to talk to them without argument but with honesty. I think they're about all the qualities I would look for in a best friend. Brightest Blessings.