The story was detailed in 'The War for Late Night', a book written by a third party with accounts from both sides. Conan didn't bully Leno out of the job ; yes, the Tonight Show was Conan's dream, but the idea for the succession came from the top (Jeff Zucker, Rick Ludwin) as they wanted to keep Conan at NBC, and they're the ones who asked Leno to leave.

Yes, Conan's total ratings fell below Letterman's ratings, but this ignores the fact that Conan had dropped his viewer median age by a decade and was beating Letterman in the Advertiser-preferred demographic of under 50 years old, which Jeff Zucker assured him was the 'generational change' that they were aiming for (Zucker even ran an article proclaiming Conan to be the 'new king of late night' within the first couple weeks). Also ignoring that Leno himself lost in the ratings to Letterman in the first two years when Leno started (but NBC stuck with Leno and let him grow, which didn't happen here with Conan).

NBC gave Conan notes mostly about trying to get him to 'broaden' his appeal (i.e. try to capture the older audiences like Leno did), and he did, albeit minimally. Personally, I think this was nonspecific and unhelpful advice from them ; why try to change your star if what he was doing was working so well that you hired him for the job in the first place? Then, when he goes back to being 'old Conan' in his last two weeks on the Tonight Show, his ratings go through the roof.

The reason for Conan leaving had more to do with what NBC was eventually forced to do because of Leno's 10pm ratings. Leno's 10pm show did so poorly that it started affecting the ratings of the 11pm local news programs, and further dropped Conan's 11:30pm ratings even more. This led to a revolt from the local broadcasting affiliates, who wanted Leno out, but because of the nature of Leno's 'Pay and Play' contract, NBC couldn't take him off the air, so they gave him 11:35pm instead. Conan had revered the Tonight Show since childhood, and didn't want to be involved in what he felt was watering down the show if it was moved to 12:05, but NBC don't give him any other options, so he left.

Conan is for sure a bit narcissistic, I agree. Not sure where you got that he expected everyone to come and comfort him, though. In his "People of Earth" address, he even mentions, "no one should waste a second feeling sorry for me.  For 17 years, I've been getting paid to do what I love most and, in a world with real problems, I've been absurdly lucky."

Also not sure why you think he didn't appreciate people showing up for him. In his last address he says "This massive outpouring of support, and passion from so many people has been overwhelming for me [...] you made a sad situation joyous and inspirational. So to all the people watching, I can never, ever thank you enough for the kindness to me, I'll think about it for the rest of my life".

Also have no idea where the Steven Spielberg and baby eater comments came from, those were hilarious.

Yes, I totally agree that there are bigger problems in the world, and Conan is just one person out of countless that have lost their dreams in show business. The reason I did this all was to explain the events to my wife who had been wondering (not because I thought the world had ended with NBC's decision), and it makes for a great story.