Sean Penn explained his much-discussed absence from the Academy Awards in March, where he missed out on accepting his third Oscar in person, while appearing at the Tribeca Festival in New York on Friday for a Storytellers series moderated by CNN’s Kaitlan Collins. The intense, supremely talented, and at times mercurial actor and global activist was at the festival a year late, after having to cancel his planned 2025 slot because of a death in his family. On Friday evening, he sat with Collins, who hosts The Source with Kaitlan Collins weeknights on the cable news channel while also serving as the network’s Chief White House Correspondent. Penn won his third Oscar in March for best supporting actor for his role as repressed oppressor Col. Steven J. Lockjaw in Paul Thomas Anderson’s lauded Best Picture winner One Battle After Anothe r . This added to his best actor wins for Mystic River in 2004 and Milk in 2009.…