She was a day tripper,One-way ticket, yeah

there are Dozen songs (maybe two dozen) by the Beatles
        with words that are so fuzzy that i've been wondering
                                   about them for 30+ years.
                    -----   i guess they are all [John] songs.
(Paul's songs are straightforward... like the one
               about breaking up with his posh then-girlfriend.)
e.g.  and if the sun doesn't come, you
                get a tan from standing in the English rain
a [Glass Onion] is a Trinket?
happiness is a warm gun... is a metaphor?  of what?
Day Tripper -- Song by The Beatles
Got a good reason
For taking the easy way out
Got a good reason
For taking the easy way out, now
She was a day tripper
One-way ticket, yeah
It took me so long to find out
And I found out
She's a big teaser
She took me half the way there
She's a big teaser
She took me half the way there, now
She was a day tripper
A one-way ticket, yeah
It took me so long to find out
And I found out
I tried to please her
She only played one-night stands
I tried to please her
She only played one-night stands, now
She was a day tripper
Sunday driver, yeah
It took me so long to find out
And I found out
Day tripper, yeah
Day tripper, yeah
Day tripper
Day tripper, yeah
Day tripper
Meaning in the Song:          The song uses "day tripper" metaphorically to describe a girl who isn't interested in a serious commitment, but just a casual fling.