As a footnote, legendary DJ John Peel rates this as his favourite song, and indeed 'probably the best record ever made'. Apparently, he cried when he first heard it.
Sharkey's desperate vocal delivery is part of the song's appeal; a second component is the fact that, apart from the squalling punk guitars, 'Teenage Kicks' could have been released at any point in the last half-century without sounding out of place. It could have been written by Buddy Holly, and has a deceptive simplicity to it that grows with time.