The video was viewed nearly 500,000 times in 24 hours. The vast majority of comments showed that many viewers believed the claim to be true. Some commenters also noted that part of the lyrics for the song contained the words, "I just want you to know who I am," which they related to Trump's personality.
However, the video was nothing more than a joke. Trump's Associated Press interview from Oct. 16, 2018, mentioned nothing about a "favorite song" or "Iris" by the Goo Goo Dolls.
BBC News reported on the meaning of the song, and how Trump connected it to his own life:
The president is a big fan of The Rolling Stones, Eminem and Elton John (a decidedly one-way relationship), but his favourite song is Peggy Lee's Is That All There Is? It's an interesting choice: Lee's nihilistic ballad essentially says life is a series of meaningless disappointments, so you might as well drink away your sorrows and forget about the rest of the world.
Mr. Trump sees it differently. "It's a great song because I've had these tremendous successes and then I'm off to the next one. Because, it's like, 'Oh, is that all there is?'" he told his biographer Michael D'Antonio, in 2014.
In sum, Trump's favorite song was not "Iris" by the Goo Goo Dolls. The TikTok video that made the claim was simply a joke.