You could quite reasonably consider an excited electron to be a 1-bit memory of experiencing a photon recently. My understanding of panpsychism is that it doesn't require everything to have an equally sophisticated consciousness/experience as ours, just some. And sure, an excited electron decays, but so do your memory and bits in RAM.
Well I suspect a memory system, together with stable input/output hardware, are necessary but not sufficient. To be a conscious agent, said agent's memory must include a representation of itself. Otherwise it can't truthfully say, "I see a pebble."
Edit: it can't truthfully think, "I see a pebble."
