Why do humans have fear when we love?

1 John 4:18-19-states a few things:-
There is no fear in love.
Perfect love cast out fear. Fear involves torment.
He who fears has not been made perfect in love.
We love Him because He first love us.

Life seems to tell me otherwise:
There seems to be fear in love. When one choose to love, there is the fear: the fear of rejection.
When one choose not to love [ to feel and sympathize and care for another ], there is no fear of rejection. So love is the source of that fear rather than the antidote of fear. But once the fear is acknowledged, it is the perfect love of God [ who is love ] that casts out that fear as we are being perfected in that love. It is that Agape love that takes into account the possibility of rejection. The rejection does not negate that love.
So the more we immersed ourself in the unseen Him who love us , the more we are willing to love our fellowmen whom we can see. [ 1 John 4:20 ]
Do we have a choice? If we really do want to experience God's love we have to love our brother also - 1 Jn 4:21. Keep loving, and the torment of fear [ not the fear itself ] will dissipate.
Love is patience, kind, does not envy, is not boastful or proud, does not behave rudely, not self-seeking, not easily provoked, thinks no evil, does not rejoice in the iniquity, but rejoices in the truth. Love bears all things, believes all things, hopes all things, endures all things. Love Never Fails. 1 Cor 13: 4-8