If you redo a DIY, does it cancel it out? Or - repainting my stencil wall

It's been a long time since I painted a room or made major decor changes in our townhouse. It was a huge accomplishment to decorate it the way I wanted it, and it felt like a complete project... so I've been just living in it for a couple years! But, I have the bug for a new project and since our moving plans didn't work out this summerand I don't have the perfect "cosmetic fixer" and spare cash