If there is any bit of advice I could give to anyone from my very limited and unwise position in life, it's that you need to understand and acknowledge your own capacity for harm in order to properly prevent harm from happening.
Think of the worst possible thing you could ever do, something that goes against your morals entirely. What exactly are you doing to ensure this doesn't happen? No, seriously, what's your plan, not a kneejerk reaction, but an actual emergency plan?
Sometimes prevention is simple. "Well, I don't want to kill innocent people, so I'm not running around with a sharp knife and the intent to stab." Fair enough! But realistically, harm is usually a lot more mundane and complex than that.
You don't want to hurt anyone. And if someone already got hurt by accident, then what? For most people who aim to be kind, the most harm they ever cause is often accidental, neglectful, unintentionally selfish. In thinking, "I would never let that happen, that goes against my morals entirely," without actually planning out what to do in that scenario or how to actively prevent it, you refuse to acknowledge your own capacity for harm. HOW exactly would you ensure it never happens? HOW can you curate a space that keeps people out of harm's way?
Further, do you know what to do if the worst possible thing has already occurred? Because from my experience, most people do not know how to gracefully accept that they fucked up, and they don't know how to remedy the situation nor move on with their lives. It turns into one massive fit of cognitive dissonance and one big blow to their self-esteem.
Shit happens, there's no denying it, it sucks. But it doesn't matter what you think or feel. Your guilt or your fear will not help anyone, especially not yourself nor the people you hurt. In order to actually be productive in those scenarios, you have to accept the reality of it: You fucked up, and now you need to know how to reduce or prevent further harm.
Maybe you never intend to stab someone, but you push someone over in a fit of anger or stumble into them purely on accident, and they fall onto something sharp anyway. Unpredictable circumstances, at least from your perspective, and now you feel condemned for making a mistake nobody could have foreseen. What do you do? If you had not been thinking about the impossibility of your active participation in harm, you may have been able to notice the passive ways you allow harm to persist. In focusing too much on the impossibility of active harm, you forgot to remove the sharp objects around you and allowed them to exist in the environment.
Then there's blood on your hands, and you don't even know how to take responsibility for it, let alone how to stop the bleeding.
This is both about passive bigotry and about the way I have dealt with people who allowed abuse to continue simply because they could not grapple with their own passive involvement in it. Their only answer was either begging to absolve their guilt, or a full rejection of the severity. What they craved most, either way, was comfort and reassurance that they were not a "bad person", to personally move on from the incident with their ego intact and their conscience clear.
Hurting someone once does not condemn you for life. I don't believe there's an "objectively bad person", instead I believe that there are a string of choices you can make that either help or harm people, one by one. But if you refuse the possibility entirely, shut it out completely, then in doing so you will be not only hurting people but neglecting them afterwards.
You don't need to self-police yourself, it's not about burdening yourself with guilt before it even happens. You just need to reasonably plan ahead like anything else. If there's a fire, you need to know what to do and where to go and how to keep people safe. If you hurt someone, you need to know how to handle the situation gracefully.
Please act mature. Metaphorically speaking, if you accidentally elbow someone in the face, have the good grace to get them a fucking ice pack instead of spiraling in your own guilt or telling them it's not a big deal and making excuses for it. If you find yourself with a trail of victims and the guilt eats you alive, for fucks sake try to figure out what you did wrong without opting for self-destruction. Most people just want the pain to stop and to be heard, not for you to make a show out of your self-hate or your full denial of the situation.