You can be rational in love. That is what love means.
But only after some time.
When mind games end for both of you. You really open up fully and completely. You no longer need to prove that you opened up full. You sense love and do not have to actively display it.
Love is not word play but feeling. The moment you sense your lover without words,real love begins.
Yes true unconditional love exist, even today, but yes very few reach at the epitome of it.