One day, when I get enough spare time, I will make the thing. I even have some components ready. Until then I daydream of how I will make it and how it will fi

One day, when I get enough spare time, I will make the thing. I even have some components ready. Until then I daydream of how I will make it and how it will fit together. If I never get round to it then that time will have been wasted. But if I do, all that daydreaming will have been useful mental prototyping. But was it «doing the thing»?