I have stopped seeing disagreement as rejection. Every day of our life is about negotiations. Taking things personally is irrational.
In my 20’s rejection meant war, be it in business on a personal relationship. As I am growing old, I am starting to make peace with it. I don’t see failing negotiations as rejections but a learning experience.
Is anyone preferred before you at an entertainment, or in a compliment, or in being admitted to a consultation? If these things are good, you ought to be glad that he has gotten them; and if they are evil, don’t be grieved that you have not gotten them. And remember that you cannot, without using the same means [which others do] to acquire things not in our own control, expect to be thought worthy of an equal share of them. For how can he who does not frequent the door of any [great] man, does not attend him, does not praise him, have an equal share with him who does? You are unjust, then, and insatiable, if you are unwilling to pay the price for which these things are sold, and would have them for nothing. For how much is lettuce sold? Fifty cents, for instance. If another, then, paying fifty cents, takes the lettuce, and you, not paying it, go without them, don’t imagine that he has gained any advantage over you. For as he has the lettuce, so you have the fifty cents which you did not give. So, in the present case, you have not been invited to such a person’s entertainment, because you have not paid him the price for which a supper is sold. It is sold for praise; it is sold for attendance. Give him then the value, if it is for your advantage. But if you would, at the same time, not pay the one and yet receive the other, you are insatiable, and a blockhead. Have you nothing, then, instead of the supper? Yes, indeed, you have: the not praising him, whom you don’t like to praise; the not bearing with his behavior at coming in.
Enchiridion of Epictetus