You can plan for the things you know about, it's always the things that come up out of the blue that trip you up.
My husband is trying very hard to get LPA for his dad.....bit of an uphill task! It is comparatively cheap for peace of mind, and remember it only kicks in if your dad is no longer able to do it for himself....in which case wouldn't it be better for a loving family member to be able to easily manage his money for him? And the H and W one would enable you to arrange/challenge anything to do with his healthcare, living arrangements etc instead of being shut out of decisions. Make use of his current independence to ensure you can help him later down the line.....and good luck with the conversation (try getting someone his own age to talk to him about it)