Imagine you’re seeing yourself mocking Jesus, whipping him, driving nails in his limbs, etc. with a certain vice in a thought bubble (nothing graphic)–what really made Christ’s Passion the most painful–and not being able to stop yourself, as you are blocked by a plexiglass window, maybe. If you’ve seen the scene in Terminator 2, where Sarah sees her old younger self at a playground with her son and then sees a nuke hit and all going to ash, except she didn’t do it to anyone.
Also, imagine seeing yourself put a sword into Mary’s heart and not being able to stop yourself. It would be like watching a horror film, where you shout, “You idiot! Don’t go there!” to the future victim, except you are telling that to yourself as the homicidal crazy person going to do harm to one you wouldn’t hurt when thinking clearly.
It might be something to contemplate. Where you there when I crucified my Lord, might be the better line.
You can then imagine a picture I saw, where Jesus is lifting up a passed-out-looking young man in a t0-shirt and jeans with a spike and hammer. Hopefully, you can then picture yourself like St. Peter after having denied Christ 3 times.
It may not cause a metanoia, but I’m sure God cares we feel bad about what we’ve done. Of course, we’d have to confess our sins and avoid the near occasion of sin as much as possible to receive the necessary benefits of the love of Christ portrayed in the image in the last paragraph–esp. if you committed a mortal sin or many of the same venial sins as being at least not mortal. I even apologize to my Guardian Angel for causing the angel so much trouble in watching over me.