There are so many simple tasks you can do to help those with Dementia to make them feel less alone, some examples of this are: Visiting them often, take them out for the day, spend time just talking and listening to what they have to say. It's important to spread the word and getting others making the change, as one small change that they make can have a HUGE impact on somebodies life. I am in no way claiming to be an expert on the topic, but similar to most illnesses the best way to help somebody is by being there. Whether they remember it or not, you were there and that is all that matters. At that moment in time they loved it and were having fun so why not keep doing it. Giving someone that feeling of happiness is one of the best things you can do.
If everyone made some sort of movement to help those struggling with this, the world would be a better place. You have no idea who it is going to effect and at one point of your life it could effect yourself. Think how you would like to be treated whilst going through this life destroying illness and treat others like you would like to be treated. You can do something as simple as dedicating an hour a week to someone who is alone, working with charity movements, just telling your friends and family about how they can help someone with dementia or something along those lines. There are so many things you can do to help change a life, you can be that change.
If it becomes too much for you to care for a loved one with dementia, there are other alternatives to give them the best care which you can check out here.