Guilt is Universal? Sounds right.
But I really am unsure what people mean by Catholic guilt. Sin is missing the target. The target is that which is good. Thus the lack induced by missing it is a lack of some good. Who's fault is it that there is less good? Whoever did the aiming. That's me. I am guilty. That is the reality of sin.
But guilty doesn't mean culpable and it doesn't mean shame. It is hard to fault someone for missing a target that they were unaware of. If you thought the target was the tree 3m to the left of the target I can't fault you for hitting that instead, but there is still less good in the world as a result and it is still your fault.
This is why Catholics emphasize the duty to inform your conscience. By studying God we can learn what we should really be aiming for. You might phrase it in a secular way like "be a little less wrong every day"
This is also why God seemed so selfish at Mount Sinai. The first commandment he gave was. "I am the Lord your God you shall have no other gods besides me." This sounds like He is full of Himself. But what is really happening is that God knows that humans focus on, or aim, at the thing they worship. If you constantly think about money, that is were you will aim, that is effectively what you worship.
Aiming at God means aiming at the purest ideals you can conceive of. Perfect love, perfect truth, perfect justice, perfect beauty. Never being satisfied with our understanding means we can get ever closer to hitting the mark.
Shame is not something encouraged by the Catholic Church. That is the Devil discouraging you from aiming higher. Those are feelings that creep in when we know the target, but miss on purpose, because we value something other than God. Add an "o" for the atheists. We value something other than the Good.
The real things you will find we emphasize are forgiveness and mercy.