The Rabbeinu Bachye does not directly comment on this verse in the first portion of Breishis, but we can glean a whole new insight based on the fact that he quoted it to explain why Yosef named his firstborn Menashe. It would seem strange that Yosef could forgot his father or would even want to forget his father, one of our forefathers, one of the greatest people in the history of mankind, who loved him and favored him more than any of his brother. Indeed, he was his prime talmid [pupil] in Torah learning; why would he want to forget such an illustrious person?
Furthermore, we know that Yosef did not forget his father. For after Yosef revealed himself to his brothers and sent for Yaakov to come to Egypt, the Torah says: “And the children of Yisrael did as they were told and Yosef gave them wagons upon the orders of Pharaoh and he gave them food for the way” (Breishis 45:21). The Rabbeinu Bachye comments on that verse that Yosef sent a sign to Yaakov that we were separated from each other when you were teaching me the topic of eglah arufa. For this reason the Torah later says: ‘and he saw the agalot (wagons), and Yaakov’s spirit was rejuvenated…;”meaning, Yosef remembered exactly what he was learning with his father at the time he was sold to Egypt over two decades ago! So what, according to the Rabbeinu Bachye, does Yosef mean when he says: “G-D has caused me to forget… all my father’s house?”
We must say therefore that of course one does not need to forget his past, and in fact Yosef did not forget his. But in order to have ultimate quintessential marriage, one must view him or herself as if he or she completely forgot their parents’ house when they enter into marriage, in order to build a new, more powerful relationship with one’s spouse. The home they build should be focused on developing the relationship between them, creating a bond of unity between themselves and no one else.