Hi,
a recollection from the past still works wonders in my memory (or on my memory?)
This is an odd sentence in terms of meaning. If you have a recollection, it means that you remember something. If you already remember something, how can that thing affect your memory?
Generally speaking, if something works wonders on your memory, it means it improves your memory.
If something works wonders in your memory, I'm not very clear on what this means. Perhaps it makes you feel happy? It's an odd expression. I suggest you say it another way.
Best wishes, Clive