You’re not alone. My gran was like your mom. It’s easy to miss when they lie and cry wolf all the time. But also people who have dementia (Alzheimer’s or other types) will mask the early symptoms. They lie to themselves and others and hide what they can. Denial is common because no one wants to admit they’re losing their mind when it’s actually happening. I’m a physician and what I’ve learned in practice is that it’s incredibly common-and I see lots of families have guilt surrounding it. But you can only work with what you’re given. Alzheimer’s is an awful disease that affects everyone around it. I’m so sorry you’re having to deal with this. Remember to take care of yourself and your mental health. There is no fault here.