For someone who never had a best friend in my life, I find the concept of best friend difficult to understand.
No matter what people will change they will turn against you in a heartbeat. You never know when that will happen and you have to keep cards close to you. At least that’s what I believe.
Instead what I have are friends. I have equally similar relationship with them all, and maintain a relatively good distance.
I expect them to be loyal but at the same time I’m always ready for them to turn their back on me.