Greed and the way to fight it

I started my wonderful, tearful journey of crypto investing one and half year ago. Yes my first purchase was in last May, yes before the fall. FOMO won that time.

Since then I was in green and in red aswell. Mostly in red. I had the chance so many times to take profit. I had so many succesful postions in leverage trading.

But greed kicks in every time. I'm sure most of us suffer losses thanks to that.

So my question is: How do you say no to greed? Do you have a goal to reach and if you've reached it can you stop? Can you be statisfied with the profit after seeing that you could reach higher?

If you can then teach us how to do it. Tell us the method so we may learn.