Aging parents who have a history of lying and denial. How can I help?

My Mom has lived in a State of Denial, up that creek sans paddle, most of her life.
It took epic efforts to talk with her and come to some workable solutions regarding planning what to do for when she dies.
Even then, she can switch at any moment--her specialty is turning 180 degrees on a split-second dime.
We finally came around to her understanding the altruistic sense of body donation--hey--it's free. They harvest tissues for research, cremate the remains. Will either ship cremains back to family, or handle it themselves.

There are evidently a number of these places across the country.
There's a place in Portland, Oregon-- I think they serve the entire west coast for picking up remains from locale mortuaries that do the body pickup.
There are forms to fill out and get notarized.
Mom actually went through with that--completing anything is not her forte'.

But handling finances was something else.
She's been a terror with money--mostly disappearing it in many creative ways. So she lost it all and had nothing but a tiny SSI to live on.
She's a controller, so hates to give POA to anyone--most we could get her to do, is a hand-written, dated, signed paper saying who she allows to handle her paperwork and bills, etc.
This concept appealed to Mom's altruistic ideals of helping people, helping science, and possibly the world
[yeah... a bit grandiose, but for her, it worked...at least for now! ]

I don't think Mom will ever realize she can't live alone, much less rustically in the woods! She doesn't fall for "I could help my kid financially by living with them paying rent"....she thinks people are stealing from her all the time.

How it's handled kinda depends on how lucid a person is. the more dementia or behavior issues there are, the tougher it gets, too often.
Jennegibbs had some good suggestions!

And yeah--at this stage in life, elders who've had behaviors like that all along, aren't likely to change those.

I hope you get lucky and can get some final arrangements done.

What exactly do you want them to do at this point? Why? If you can answer those two questions, you might have a better chance of getting them moving in that direction. For example, if you want them to do something for your convenience (because you know you'll be the one who has to handle it when the time comes) try the approach of being upfront about that. Are they likely to do something for your sake that they otherwise consider unimportant? Do you want them to do something for each other? So that the one who survives longest won't have certain issues to deal with? Would that appeal work with them?

My mother's life-long coping mechanism has been denial. It would be cruel to take that away from her without giving her some other way to cope. It is not always clear to us how to do that!

We were able to get her to pre-pay for her memorial service. Evidently she is not in denial about eventually dying. We convinced her that is would make it much easier on us when the time came if she'd already chosen the funeral home and had plans in place. So she did it for us.

Similarly, when she could no longer live on her own (about which she was in denial, of course) we finally persuaded her to move in with a daughter by taking her aside and telling her that this daughter couldn't afford her mortgage since she retired and she was going to have to rent some rooms. She'd rather do it with family. Oh, well, then, Mother could certainly move in and pay her rent! Not that she needed it, of course, but that she'd do it for one of her children. Sigh.)

We've had a few successes getting around her denials, but many more failures. Do what you can. Don't beat yourself up for what you can't make happen. MikeGood's somewhat indirect approach sounds good to me.

I wish you luck!

Remember, you can’t force people to change their minds and do things they see no value in doing. The goal is to let them to come to realizations so they can make decisions on their own (at least let them think they are making them on their own☺). If you can, plan to have a series of conversations. Rather than having conversations about life issues, try guiding the conversations by bringing up similar events that have occurred with other people (friends, family, neighbors, or celebrities) and how it has affected their families. Ask your loved one what they would do. Listen and guide. In a follow up meeting, now that their thoughts have been stimulated by the prior conversation, try turning the topic towards your concerns. Let them know that you love them, respect their wishes, and want to support them. Speak in general terms about their health. Don’t use words like Alzheimer’s, dementia, or disease. If they do show you documents such as those mentioned by Eyerishlass, make sure they are up to date.

Since they have a history of dishonesty don't take anything they say about their end-of-life planning seriously. Ask for proof.

Talk to them about becoming their POA. That's at least something you'll have in place when the time comes. It won't cover every issue you'll face with them but at least it's something.

Also talk to them about an advance directive which would give you the legal right to make decisions on their behalf if they are unable to do so.

These two things are vital to have when our parents are elderly. They're very simple and straightforward and a good place to start.