[sifar]

There are multiple ways to look at this.

One is to stay small - the things you do matter in your individual sphere.You don't take care of your body, you die. You don't exercise your brain, it atrophies. You can increase this sphere to friends, families, community etc till you can see the effects and have feedback. Of course as in all system, those might be a bit delayed, so it helps to have some context.

Or you can go meta, why should things matter. This innate drive that we have to find meaning in all things is very confusing. Things simply are - accept them.

And if nothing actually matters at all - then you have a blank canvas to paint what you want.