A Professor at Ohio University in the US has gone viral after a very touching answer to a student's question.
Assistant professor Dan West teaches a class called Introduction to Human Communication, which includes a section on love and relationships.
In a recent session, West opened the floor to questions from students. He had no idea one question in particular would catapult him to viral internet fame.
A student asked West in class: "How do you know when you're in love?"
According to Buzzfeed, West's answer started with the obvious: "it just hits you".