I can finish most official sets in a weekend. The steps are clear, the bags are numbered, and everything is designed to be straightforward. Custom builds take longer. I have to sort parts myself, check the instructions carefully, and sometimes redo sections that didn't work the first time. But because it takes more effort, I remember the build more clearly later on. There's something about the slower process that makes it feel more meaningful. Anyone else find that custom builds stay with you...