This is a nice way to express it, imo. I also think it's possible to interpret what happens differently. A balloon or something in space doesn't have anything

This is a nice way to express it, imo. I also think it's possible to interpret what happens differently. A balloon or something in space doesn't have anything to move against, whereas the chair's wheels are on the floor. When you move the weight in an environment without anything to respond to, ie in suspension in a vacuum, there is no opposite to respond or work against. Both seem possible to me - that a chair+person-with-weight is capable of generating it's own momentum and that nothing happens in space, in a vacuum.