And The Early Church Fathers (successors to the Apostles) disagree with you. You view a lot of truth to be nonsense. The question is, why do you believe such things to be nonsense? Is it for personal reasons? Do you believe certain things to justify your own actions?
I have a Protestant co-worker who believes that Mary and Joseph were intimate after the birth of Jesus, because her Husband has told her that he could not go through life not “getting any.” Do you agree with her Husband and with her reasoning?
Let me go a step further, Do you believe in the Virgin Birth? Or is this also nonsense? Do you believe, rather, that Mary and Joseph “hooked up” prior to being Married and made everything up?
Why do you believe what you believe? I can show you other places in Sacred Scripture where the term “brother” and “sister” are used and it does not mean biological brother and sister.
In Geneses 13:8 Abraham refers to his nephew Lot as his “brother,” though Lot is actually his brother’s son.
The word “brother” was also used to describe Jacob and Laban who were Uncle and Nephew.
The Hebrew word for brother (אח, ach) can refer to any close male relative of the same generation, such as cousins, nephews, or even members of the same culture. And we often see it to mean relative or kinsman in Sacred Scripture.
Same goes for the word “sister.” It can mean close female relative, like a half-sister, aunt, or sister-in-law. And like brother can also mean a fellow believer or spiritual kin.
The book of Proverbs uses the word “my sister” to describe Wisdom.
Origen and Epiphanius (successors to the Apostles in the 4th Century) believed these “brothers” and “sister” of Jesus were St. Joseph’s children from a previous Marriage.
St. Jerome, who lived in the late fourth century and translated the Bible into Latin, believed that the “brothers” and “sister” of Jesus were cousins (belonging to Mary and Clopas).
If you would like to read more about this, I invite you to check out “Jude and the Relatives of Jesus in the Early Church” by Richard Bauckham (it is a bit pricey, because it is an academic book).