Don't feel like going to the grocery store today? See if you can send your brother as a proxy, meaning he's a substitute authorized to act for you.
Now, don't get crazy about getting your brother to do everything for you. Running your errands is one thing, but if you're a historian and your brother is an accountant, he is not a good proxy for you when you don't feel like researching your book about Napoleon. And you wouldn't be a good proxy for him in his work. A proxy must be well-chosen to truly act on another person's behalf.