...of All Time".
Paul was just being humble, with that statement...
"Norwegian Wood" is generally credited as sparking off a musical craze for the sound of the Sitar, as played by Harrison. In the mid-1960s, a trend which would later branch out into the raga rock and Indian rock genres
The song is now acknowledged as one of the cornerstones of what is now usually called "world music" and it was a major landmark in the trend towards incorporating non-Western musical influences into Western popular music. Harrison's interest was fueled by fellow Indian music fans Roger McGuinn and David Crosby of the Byrds, whom Harrison befriended in August 1965.
Harrison would eventually be transfixed by all things Indian, taking sitar lessons from renowned Indian sitar player Ravi Shankar.
Not to mention...what's so wrong about love songs?