I feel the sadness too. It comes and goes in waves. As time goes by, we will become accustomed to new coinage, notes and stamps with the King's head on them, public buildings with heraldic emblems changed to the King's crown. It will be a long time before E II R disappears from public consciousness. There are isolated post boxes still with V R on them. King Charles III was a man of many opinions when he was Prince of Wales. He might find it hard to have to contain them now he is King, as his mother did.
For most people nothing will practically change, yet somehow our world is different today from yesterday.