Mortal Sin: Retrospective Effect?

[Tannhauser]

If we remember something that we have done in the past, that retrospectively we understand to be mortally sinful, but at the time we were either unaware it was mortal sin, or it did not occur to us, and so it was not subjectively imputed to us…

Are we obliged to confess such retrospective sins?

My understanding is that we are only to confess mortal sins as those sins that we have (/had) full knowledge of… and thus retrospective effect is not applicable.

Please help.

 

[Mijoy2]

If I was to confess every “mortal” sin I recalled from my past, I would literally require a full time priest to follow me around every moment of every day.

I was assured when I mentioned this in confession, that confessing all my past sins in general manner (after 35 years) was sufficient.

I’ll trust in this priest’s assurance.

 

[momor]

If you didn’t know it was a mortal sin at the time it happened then it’s not mortal. You have to have full knowledge and consent. But there is no reason not to confess it anyway. I would for the grace it would give me and for the pastoral advice I might get. There could be a good reason you are remembering it now. The Holy Spirit works in mysterious ways.

 

[NHInsider]

Agreed. There is no harm in confessing the sin later, even if it wasn’t mortal because you didn’t have full knowledge. We can’t overdose on grace! But we should not obsess about such things, either - it’s not like God is waiting to see if we remember everything and planning to “zap” us if we miss one . . .