My father says one thing, does another. How can I tell how he truly feels?

Says he feels one way one day and completely flips and goes the other way the next. How can I tell which he truly feels when he says he hates this today and tomorrow he'll say he loves it. Is there something else going on here? My father always wants to make everyone happy and will tell you what you want to hear even if it's not what he truly believes. How can I tell what's real and what isn't? He loses things all the time and can't remember he set something down only a short time before. I know stress affects memory and he's definately been through a lot of stress in the last two years, wife of 30 yeas died, he almost did, moved to another state to live with me and my husband, got married and divorced within 8 months, and now back living with us and has to file bankruptcy because the wife of 8 months spent every penny he had and maxed his credit cards. But are the memory problems a result of stress or something else. Are the changes in opinion or what he cares about also a result of stress in that he can't remember how he felt? I love my father very much and I couldn't be happier that he's living with us, but I'm concerned about his health. Sorry this is so long and so scattered. Thank you in advance for your suggestions.