Protective Magic

After finishing the prophecy about the Horcruxes, Albert did not hurry to leave the Headmaster's Office. Instead, he chatted with Dumbledore as though he had run into an old friend he had not seen in ages. However, Albert soon led their conversation off course. It first turned into an academic exchange, then into a pattern where Albert asked questions and Dumbledore helped answer them.

Although Dumbledore had not paid much attention to academic matters in recent years, he had once been a professor at Hogwarts and was quite willing to clear up Albert's questions, given how diligent and eager to learn he was.

However, when Albert pulled a Quill from his pocket and began taking notes, Dumbledore started to wonder whether the Sorting Hat had put Albert in the wrong House.

Their exchange was fairly pleasant, though the topic was rather dull, causing the portraits in the Headmaster's Office to close their eyes and rest.

An hour later, Albert had consulted Dumbledore on each of the questions in his original notes.

Another half hour later, Albert left the Headmaster's Office with the Ancient Runes notebook he had borrowed, thoroughly satisfied. The notebook contained Dumbledore's research into Ancient Runes.

Tonight had truly been fruitful, and he really had his thick skin, honed over the past few years, to thank for it. Albert had said that he intended to write a "Runes Book" and hoped to receive Dumbledore's help, occasionally coming by to discuss Ancient Runes with him.

So Dumbledore had generously lent Albert his old notebooks.

There were actually very few experts in the entire British magical world who were skilled in Ancient Runes. If those notes were not lent to someone, they would eventually just gather dust, perhaps even be forgotten completely. If he lent them to Albert, perhaps the