You may strive to be like them, but seek not to make them like you. For life goes not backward nor tarries with yesterday.
— Kahlil Gibran, "On Children" from The Prophet.
I'd also recommend reading Kahlil Gibran's wise words on marriage, which pop into my head on a weekly, if not daily, basis — especially this last part:
Sing and dance together and be joyous,
but let each of you be alone,
Even as the strings of a lute are alone
though they quiver with the same music.
Give your hearts, but not into each other's keeping.
For only the hand of Life can contain your hearts.
And stand together, yet not too near together.
For the pillars of the temple stand apart,
And the oak tree and the cypress grow not in each other's shadow.