If you want to know why it sounds similar, it's because Dr. Luke, the producer of both songs, use nearly the same chords for both, just switched around.
I can't listen to this video every thursday because all the radio station keeps repeating the die young song and the good feeling song everyday while I was listening to the radio station every monday, tuesday, and wednesday.
Florida stole it form Avicii and KeSha sampled with permission ( I think ). FLorida stole from Kesha more than once as well. Will I am also stole this melody, some songs of his feat Miley Cyrus ... Let's get reductive ;)