It. Is. On.
Not having fun with your dementia person? Then it's time for some forced dancing! That'll teach 'em to keep that upside down in a frown.
Ideally you'll want to force dance 'em on a day when you're feeling particularly goofy (potentially even still drunk from the previous evening's hijinks). That way you won't even register your dementia loved one's disdain for the activity as you haul them into your arms and force dance the crap out of 'em.
Did you see that sort-of smile there? Forced dancing works! Well, kinda... she went on to have a pretty pissy day, but for a few minutes that morning she was suffused with the happiness of forced dancing hell.
P.S. This isn't the last of the forced dancing: Forced Dancing 2: Riverdance!