You might not understand why you are being downvoted since you are new there.
Don't take it personally, is just that we don't want any kind of humour or otherwise pointless (as in: adds nothing to the conversation) informations.
We are trying to keep the signal to noise ratio high, just say something only when it adds to the conversation and you'll do great!
I don't think it's that we don't want humor—there is plenty of that on HN. I think it's that "lmao" is better conveyed (and with less noise, as you say) by an upvote.
