We all know Harry gave the elder wand to Dumbledore's corpse. But later communicated with his portrait about where he was keeping the wand and why.
"I'm putting the Elder Wand back where it came from. It can stay there. If I die a natural death like Ignotus, its power will be broken, won't it? The previous master will never have been defeated. That'll be the end of it."
—Harry's decision to give up the Elder Wand
So, why didn't Dumbledore explain everything to him in the first place if he could communicate ? If he had done so, Harry need not peek into Snape's memory and it would have been far more easier psychologically for him isn't it?