"LOL"-type responses generally don't go over too well here. In fact, humour in general is strictly forbidden. It's kind of like smuggling drugs across the border: you have to hide it really well.
No worries. It's not that humor is unappreciated, rather that people tend to come to HN for relevant information and insightful commentary (by internet standards, at least). Many early adopters of reddit came here as the SNR there dropped, and while we're politely asked not to say HN is becoming reddit, it's still a worry for many. Thus, when people see flippant comments that don't really add a huge amount to the conversation that couldn't be achieved with an upvote, they tend to downvote them. There's nothing wrong with that, as that's what the down arrow is there for, but it can take some time for a newcomer to learn the ropes and figure out what kinds of comments are or are not appreciated. Whenever I see someone who's plainly confused, I try to help out.
Thanks for the information. I try not to post anything that is meaningless. In that comment, I had asked a genuine question after the word "LOL". that LOL was there because I found the prior comment funny. I will take care from now. Thanks once again!