Will Shakespeare is still in Stratford. Anyone want to drink with me?

[Aristus]

3. "Alas, por Yorick! I knew him, Horatio."

It's obvious Hamlet held Yorick in high regard. One of the occupations of the court jester was to play with the royal children. He was like a governess/playmate who would have spent a great deal of time with the royal family. Hamlet loved Yorick, no doubt.

Court jesters were not just stand-up comedians for the king. They very often served as royal advisors to the ruler of the kingdom. One reason for this was their unusual license to speak plainly to the king, without a lot of court manners that could cloud wise advice. They did not have to be obsequious to the king, allowing them to give the king an unvarnished opinion.

Hamlet no doubt would have valued Yorick's counsel in the matter of Claudius' treachery. Yorick's love for Hamlet would no doubt have superseded his duty to King Claudius.