[King Prout]

I hope she is not so foolish. I cannot be changed.
I can be motivated to change myself to some limited degree, but the basics are set in stone.

[First Amendment]

Another interesting point is that happiness comes from within, and if both parties know this, they won't blame each other for any miseries that come naturally by the passage of time. If both parties have similar basic philosophy of life, then mutual commitment can be very good and helpful.