It's a matter for personal taste. Me personally, I discovered the early stuff when I was very young. Into my influential teenage years I discovered that there was more than the red album. I began to think I was COOL for knowing much more of the later stuff than my friends. Obviously I was'nt that cool but I'm highlighting that everyones journey with the Beatles must feel like a personal one.
As a result I think there seemed more to discover later on, lyrically, image, beliefs, art. They seemed to break the corporate shackles of their suits.
Now I know that there is so much early Beatle songs I still have to familiarise with.
The best way I can describe coming from my point of view is that The Beatles songs mean something different every day. You can grow into them, out of them and then back in. Something happens and all of a sudden you can hear the words/music differently.
I'm sure other people will have their explanations.
All The best!!!! Interesting topic.