I am a lapsed Catholic, but I respect the Church’s right to insist that Catholics respect church teaching. Every Christmas, I attend church with my elderly Catholic mother, because it makes her happy for her children to be there. I do not receive communion, but my lapsed Catholic sister (a liberal), and her non-Catholic husband (also a liberal), both receive communion every year. I regard that as liberal entitlement.
Any offense against God Himself or the things of God is objectively grave, simply because of "what it is" --- in this case, the Blessed Sacrament, the most Holy Object in the visible Universe. In a way, the Eucharist is the purpose for which the Universe was created in the first place: for a Communion of Love.
However I did not have the consciousness at the time that this was a sin of desecration/sacrilege. I think the Psalmist prays for God to free him from his unknown faults. I believe God looks mercifully on my ignorance.
Hope I hope I hope.