My mum lost the ability to do simple tasks several years ago and her short term memory was going but on the surface, to people who dont know her well, she appeared to be pretty 'normal'. She could put on a good public face and fllo people that she was ok, but at home my dad was doing everything for her (cooking, cleaning, laundry, helping dress her, feed her, taking her to the toilet etc). About 5 years ago she lost the ability to read and write and could no longer do things like safely make a cup of tea. It was because mum had such a good 'public' face that the professionals didn't pick up on how bad things were for a long time, during appointments mum seemedd very lucid etc, my dad has never been one to complain or pour out his worries so when noone asked how she managed practical day to day tasks my dad didn't say anything (i think he wanted to protect mum's dignity). 2 weeks before mum was admitted to the psych ward my sister spoke to the CPN who told my sister mum was just 'having a few memory problems', my sister filled the CPN on the fact mum could no longer do anything for herself, was unable to read, write, feed herself, carry out personal care ... The CPN had never asked about any of these things because on the surface mum didn't seem too bad. I would have thought in her job she would be used to having to read between the lines and not always taking things on face value, but obviously not!!
Over the past 18 months her memory loss escalated and now she doesn't always recognise us, has no memory of her home for the past 40 years, believes she is a teenager and her mum (long dead) will be worrying about where she is. She can no longer do anything for herself and is totally reliant on nurses. Her communication is failing fast and she now struggles to get words out and she doesn't understand what we are saying to her. She is now becoming incontinent.
The very first signs that there was something wrong were short term memory issues- repeating the same thing several times during a short conversation, asking a question that we had already been asked and had answered etc. Things remained at that level for a long time memory wise but during that time she lost the ability to do any practical tasks.
One thing I have learned with dementia is that there is no 'normal' progression. Every dementia sufferer will take a slightly different path. That is why I have found this site so helpful as it brings together people with a wealth of experience. No matter what you ask on here someone will have an answer because they will have had a similar experience!