Fallon was among the last late-night hosts to send off his Late Night and Tonight Show predecessor from late-night television. "Congratulations @ConanOBrien. One of the funniest brains in comedy," Fallon tweeted Friday morning. "Without you, I wouldn’t have a job. Thank you for everything. I’ve always said - you can’t spell HBO without at least one of the letters from CONAN." Fallon made his late-night talk show debut with Conan in 2000.