life is full of uncertainties and love is never rational. One can always think of thousands of reasons after an unsuccessful love adventure. Nonetheless, when one was in love with the other party, one wouldn't be able to analyze that carefully. Plus, don't we all agree that to love somebody, we should love not only their good points, but also their bad ahabits as well?
In my opinion, one can't know for sure if the relationship that one is going into is really stable 穩陣" or not. Love is blind, right?
Even if you are very careful, if you believe in fate, you may fall in love with the most impossible person and you can't help it.