Non continuity

You, I see you,
I smile, you smile,
but then you leave,
and go for another.
Once more I see,
one after another,
once could have's
now no more.
Another comes along,
I never was in the first place,
that's what you say,
so that's it for me.
What can I offer?
Nothing apparently.
Here I am singing the same tune,
with the same lyrics,
in the same song.
Ouch,
I never grew up I guess...