I've had several comments with more upvotes than the memes I commented on in the first place. I don't like when this happens and feel bad for the OP. If a meme has quite a few comments, sometimes people just go to see what the comments are though.
I've also been guilty of not upvoting a meme I intended to upvote. Sometimes I just get too caught up trying to make a comment. I come back and check my comment out later and notice I didn't upvote the meme...DOH!