I live out in the countryside. The nearest store is about 2.8km away. Put on some good music, get an ice cream for the second half of the trip, it's a lovely walk. I could catch a bus back, there's a stop right by the shop, but my timing is generally shite. If I'd be halfway home by the time the bus comes, I'd rather just walk.
Bimfred
They're not producing fuel to continue the same reactions, which would be a violation of conservation of energy. They're producing fuel to run a different reaction. Less "perpetual motion machine," more "spinning a turbine to charge a battery to run an EV."
Edit: A better analogy is cracking water to capture the hydrogen, to later burn it in a fuel cell.
A Deuterium-Deuterium reaction produces Helium-3 and a neutron, or Tritium and a proton. Roughly even odds on which products you'll get. And a ton of energy. A Deuterium-Tritium reaction produces Helium-4, a neutron and a shitton more energy.
Basically, the DD reaction is used to create fuel for a more predictable and energetic reaction. From the article, seems they're also bombarding Lithium with neutrons from the DD reaction to create more Tritium. Problem with Tritium is that while it does occur naturally, it's extremely rare and volatile. Tritium has a half-life of about 12 years, so if we want to use it in a fusion reactor, we need a feasible way to produce more of it at scale.
It's all stepping stones to a greater goal though. DD and DT reactions produce neutrons, which will make your entire reactor highly radioactive thanks to neutron activation. D-³He and ³He-³He reactions produce ⁴He and protons, which are actually able to be controlled by magnetic fields and won't irradiate your whole shit. But then sourcing ³He becomes your new biggest problem.
Most of us lose the playfulness as the responsibilities of adult life pile up. Between work, family and everything else, there's just no time. But that playfulness, doing something just for the fun of it, is armor. It helps ward off depression, relieves stress, it keeps our mental health up. We need hobbies, we need things in our life that are just fun and enjoyable, and we don't need to feel guilty about taking some time to relax and unwind.