HI Annabelle, I didn't do chemo but have been on tamoxifen for 2.5 yrs. Sometimes I fell like I have dementia - lol. Clarity is no longer a strong point of time - brain fuzz is. Did some research and found Estrogen is a hormone also produced by the hippocampus - memory source. As tamoxifen blocks estrogen I reckon we are affected more speedily. You'll have heard from any menepausal woman that her memory is crap - thats because their estrogen levels are being depleted thru normal processes. Ours are doubled. I read that taking up a second language can help with this loss.