"lol" was used to react to *other people* when it first became Internet language. It meant "You really made me laugh out loud".

@OogieBoogie Language change is indeed interesting. But language is being destroyed now. Words mean anything and therefore nothing, and people don't care that they cannot define the words they use....grammar rules changing, not from normal processes, but because most people use incorrect confusing grammar so much that it becomes normal -- normal and incoherent. What's left is just: emoting.