It's quite important to understand that as we learn more about our own mind, and understand the causes of Dukkha, we don't use it as a "weapon" against others. That is, we do not want to assume they should know what we know, which may have come about through some long time of practice. With the simple one with the cigarette, sure, you don't need a lot of mental development to know that by smoking you may be influencing others. However, from mental development we do understand that we are usually quite influenced by what other people think of us, and are influenced by our peers, especially if we have struggled working with our own attachments to the Eight worldly dhammas. So try not to let the understanding that you have form into idealism and judgement of others, so that you expect others to act in ways that you would like, or to act in ways that lessen Dukkha in the world. If you can't come to Compassion straight away for these people, then it's helpful to develop a little bit more Equanimity.
First of all, try to note the judgement, "judging, judging", understanding that it arises due to our own past conditioning. What we see, that we do not like, or perceive causes suffering in the world, we would like to lessen or remove it. Yet this can be aversion, rather than Compassion. So by understanding that we are suffering from that judgement, we note "judging, judging" and try to have Compassion for ourselves first.
This does not mean that we do not have to discriminate in the world, discriminate between beneficial actions and unbeneficial actions. It is quite imperative for us to learn to discriminate to protect ourselves from unwise actions, because no-one else is going to protect us. We have to protect ourselves from bad Kamma. However, the simple technique of separating the person from the action, putting the action over here, and the person over there helps greatly; realizing that the action they may be doing may be causing Dukkha and understanding that it may not be a very helpful action. This is where we use our wise discrimination. However, we try to understand that the person who is doing it may not understand and may be ignorant, and is a human being with greed, hatred and ignorance. So we try to have Compassion for the person who is doing it.
It is quite important for us, because sometimes as we do become more perceptive of our mind, so that we understand some of the causes of Dukkha, we may then look around and expect everybody to have this understanding. And we may see clearly where other peoples' Dukkha is coming from. But we are not here to try to change others, unless they give us the permission to try to do that. We can try to influence others, but whether they accept our advice is still up to them. It's hard enough sometimes to change our own mind, let alone trying to change everybody else. It's often impossible really. Even the Buddha could not change others, he could only show the way for others to change themselves. We have to try to reflect that this person is the owner of their own Kamma, their own actions. And that if we get angry at the person, if we start judging and getting all carried away with these things, then we have allowed that person to have power over us, and we fall into their Dukkha with them. We have to try to protect our own Kamma, and try to see the judgement, see it is a conditioning, having Compassion for ourselves. Learn how to reflect that everybody is the owner of their own Kamma, and try to have Compassion for them, their difficulties and suffering.
So there is a difference between wise discrimination and judgement that just falls into aversion and idealism, trying to make the world as we would like it to be. Sometimes a lot of judgement comes about because we don't accept that Dukkha exists in this world. We would like to make the world the way we would like it to be; pleasant people following our own opinions of everything. But it is very difficult to make Samsara satisfactory, even the Buddha could not.