You shouldn't be asking yourself whether the post is sarcasm. You should be asking yourself does my post fit with the logic provided by the initial post? Then

You shouldn't be asking yourself whether the post is sarcasm. You should be asking yourself does my post fit with the logic provided by the initial post? Then if the logic fits with the logic of the initial post you should ask yourself is the logic absurd? If so then that means the initial post is absurd.