I’m not that romantic person. But one thing is for sure. The most romantic word in the world is “ I love you” from one’s significant other. = I'm not that of a romantic person, but one thing is for sure: the most romantic words in the world are from the phrase "I love you" which comes from our significant other.

No need to explain why. But I try hard not to overuse it frequently, for this is too strong a word so there’s no word remaining after that. = There is no need to explain why, but I try my best not to overuse it, for this is a strong set of words that doesn't need any other words after.