Letting Go, Lightening Up

I have a really hard time keep my life + living spaces clear and not-cluttered. No matter how hard I try, it seems as if within seconds of cleaning up, things begin to immediately migrate back to those cleared off spaces.

It doesn't help that I also have a hard time letting go of things. When I try to minimize my possessions, I find myself agonizing over every little thing. What if I need it someday? What if I'm sad that it's gone?

It's kind of incapacitating, and more than a little frustrat...