How come, all of a sudden, people have mastered the complete comprehension of 'love' and its meaning?

If a teenager posts a question concerning love, people seem to automatically jump to a conclusion that one cannot be in love at such a young age. They force the person to believe that he is simply "infatuated", but not in "love." Am I the only one frequently observing this phenomenon? Tell me, how did these people become so educated on this subject, enough so that they're able to accurately predict a scenario concerning the matter without being physically there!? This is magical!