HARRY
Love blinds us? Do you even know what that means? Do you even know how bad that advice was? My son is – my son is fighting battles for us just as I had to for you. And I have proved as bad a father to him as you were to me. Leaving him in places he felt unloved – growing in him resentments he’ll take years to understand—

DUMBLEDORE
If you’re referring to Privet Drive then—

HARRY
Years – years I spent there alone, without knowing what I was, or why I was there, without knowing that anybody cared!

DUMBLEDORE
I – did not wish to become attached to you—

HARRY
Protecting yourself, even then!

DUMBLEDORE
No. I was protecting you. I did not want to hurt you...

Harry Potter and the Cursed Child - Chapter 4 :
See this quote in the Pensive -