A former prickly TV personality tries to become a better man... a former president tries to refine his brand... on the pilot episode of the stupefyingly dull Netflix talk show MY NEXT GUEST NEEDS NO INTRODUCTION... WITH DAVID LETTERMAN (2018), the onetime innovator of late night is joined by Barack Obama for a gruelling conversation. PLUS: batten down the hatches for Ron Howard's "Hillbilly Elegy."