Nature Of Mortal Sin

[The Bus Station]

When I was about 12-13, I did some things that I did not realize were mortal sins at the time, and I know that I would be committing mortal sins if I did them now. I completely forgot about having done these things until about a year ago, and since then I have thought about telling a priest about them in confession because I feel bad about them now, though at the time I didn't realize what I was doing. I knew they were wrong, but I didn't have the spiritual maturity to realize they were mortal sins. Despite this, they always linger in the back of my mind when I go to confession, and I know I would feel better if I told a priest, but if it turns out they weren't mortal sins, then I feel it would be inappropriate. So basically:

I knew it was bad but I didn't realize it was a mortal sin (or full understand what mortal sin was itself). I have always thought about confessing it but never have. Should I? And has this invalidated all confessions I've made while purposely withholding it?

[Jaime]

Well if you don't know that what you did can be a mortal sin, you didn't commit one. Mortal sin requires that the action be of grave matter, you know its a sin, and you willingly choose to do it. If you didn't know it was a sin, you don't fulfill the criteria.

Now can you bring it up in confession? YES!! Confession isn't just for mortal sins, its about your relationship with God. Now if there is a line behind you, you might want to organize your thoughts so everyone can get in. But DO talk about the things you struggle with whether they be considered grave or not.

I actually have a confessor that I go to. I make an appointment and then I don't have to worry about lines behind me and I can focus on my weaknesses.