My thoughts on this are similar to @zenvelo.‘s I agree with @Coloma‘s first post, but I hold humans in slightly higher esteem. However, the statement, “there is no right and wrong,” can lead to a life of vacillation and indecision. Not knowing the difference between right and wrong is a basic definition of immaturity.
Having a moral compass sometimes necessitates judging other humans, but not falsely; you judge them according to your own convictions—which you may have to defend someday, so keep it real. The trick is to keep it to a minimum and stay true to your beliefs. If things change—as you wisely noted they will—and you begin having trouble with some of your convictions and therefore your judgement of others, it’s time for some self examination and reconsideration. Life is a work of art, but you have to do the work to get the art. Don’t be a hypocrite and delude yourself in believing there is no right and wrong (That would be an incredibly cowardly way to live, in my judgement!) Of course there is right and wrong. It’s slightly different for everybody. But, mostly, there are general agreements among us on what this is. Here, I’ll show you.
For example, there is a right way and a wrong way to treat your environment. Do it wrong, and you will be living in a cesspool. There is also the responsibility we have toward each other. Is there no right or wrong in working toward the greater good of this world we live in? To leaving this place a better one for being here? Feel you no inner mandate toward this? Well, you might be a bit young yet.
How about something simpler: Do you litter with impunity? If you don’t, why not? Does it bother you when you see others litter with impunity? Why? Are you wrong to judge people who litter with impunity?
How about something even simpler. How about pedophilia. Does the idea of pedophilia bother you? Is pedophilia wrong? Are pedophiliacs wrong? If you think they are wrong—like most humans who are interested in living in a stable society—are you wrong to judge them as being wrong?
It is impossible to live a life deluding yourself that there is no right and wrong. Besides, if Oscar Wilde couldn’t do it, neither can anyone else.