I cant think of an appropriate title..

I made someone angry last night. A comment which made her feel hurt and upset that she felt like crying. I really dont know how i have this "ability" to hurt someone so badly with just a sentence. Luckily she is magnaminous to forgive me after i apologise, otherwise the friendship would be gone. Was thinking...if i know how to irritate people with just one sentence, why dont i know how to make people happy in just one sentence....