I too was in elderly health care and I believe like any other relationship you can form unspoken bonds in the work place.
I think I know the feeling you speak of, would you say its fair to describe it like static electricity when you rub a balloon over your flesh but the feeling is under the skin instead of on top and its energizing in a way? I find that in genuinely happy people and people that are relieved from a certain types of stress( if they brush up against me).
I think you are helping your patients feel relieved and in terms find a state of jubilation. Consider it a pat on the back that you are doing exactly what your hearts intent is and that is helping people feel good.
In terms of daily life, few things feel better than getting up, getting clean & put together as you start your day. Like wise when finally going to sleep where you know you will finally come to a place of peace and rest.
Many of us take the ability to care for ourselves for granted. For someone that is not able to do it themselves you may be feeling their comfort, joy and gratitude.
Think of it like a receipt from the universe for your deposit into the Bank of Humanity.