We spent a weekend painting the inside of our new house. The previous owner had crazy color walls. Like one wall in the living room was teal. The master bedroom was two shades of purple. They probably loved them, so naturally, it was the first thing we changed.
Painting is generally exhausting. All the arm movement just makes you feel sleepy. The first thing we did after we moved the furniture in was take a nap.
Painting IS exhausting! I repainted the inside of my house a few years back and it was a huge job. Good luck!