This was related to the sentence "At the Pool, John was definitely willing to die for Sherlock".
.

Sorry my english seems not to be sufficiant to understand what you mean. 

I just try to analyze things like 'a person is willing to die for some other person'. Why should a person do that?
To concentrate all efforts on prevent death of a beloved person is something different I suppose.

In which situation? At the pool?
He was willing to do a lot (killing, being injured, bear his behave). But really dying...? I can't see it.

He hoped to stop Moriarty with that act.

Willing to die for a person implies to love that person. Was it love at that time? I can't see that. I presume his act was an act of desperation and the only way to do anything. He was willing to stop Psycho Jim with that opportunity. But not willing to die.

I completely disagree with suggestions that unconditional love is something reserved to blood relatives. When it happens in a friendship it turns it into something extraordinarily special, and I do believe that this is ultimately what John and Sherlock have. I also believe that John's friendship for Sherlock could have turned into infatuation had Sherlock not faked his death and disappeared. But the Fall revealed his own vulnerability, and he gets over Sherlock by investing himself emotionally in his relationship with Mary and telling himself that "this is what matters now". It is just terrible timing that Sherlock resurfaces then because it hasn't occurred to him that John had to make himself move on. Hence why in Series 3 we have John sticking to his guns and not showing much of his former adoration for Sherlock. And Sherlock, victim of his own trick, is heart-broken but accepting of John's new-found happiness.

Now we just wait and see for John to see the light again...