Nice question, عندما نقول أحبك و فإننا عادة نركز على أ المتكلم بدلاً من ك المخاطب
I think this refers to the subjectivity of love in human psychology, and how before all else, we love people because they make "US" feel good and happy ! Very interesting question !
The translation of the sentence is tricky , you are asking Arabic translation of a sentence while the sentence includes references only peculiar to English language and not to Arabic .I do like this sort of quiz translations, and if I have to get the reward of trial I would translate the sentence as follows :
عندما ننطق بعبارة " أنا أحبك " فأننا عادةً ما نعبر عن ذلك بتركيز على الذات مع تجاهل السبب أو مشاعر الآخر )
OR
عندما نحب أحداً لا نسأل عن السبب
OR
الحب أعمى
Good translation . . What's important is that you got the meaning. I don't think that the2nd and3rd suggestions are good. I'd say:
عندما نقول "أنا احبك" فنحن نقولها بتقديم الأنا على كاف الخطاب.