Grief is what happens when something you attached to is gone and your mind has to update thousands of small assumptions about the world. That's why it's exhausting: every unexpected reminder is another correction.
The five stages were originally observed in dying patients, not in the bereaved, and were never meant as a checklist. Most people loop, skip, and revisit. Anger can arrive in year two. Denial can visit on a Tuesday.
A more honest description: grief comes in waves that are enormous and frequent at first, then still enormous but further apart. You don't get smaller waves. You get more shoreline between them.
There is no finish line where you're done. There's a point where it takes up less of the day, and where remembering costs less than it used to.