I've never regretted spending time up-front on architecture and design. Of course you aren't going to write the entire program from scratch in your head. But it

I've never regretted spending time up-front on architecture and design. Of course you aren't going to write the entire program from scratch in your head. But iterating through stages of written descriptions, diagrams, actual code, and unit tests tends to produce a much higher quality result in the end than just banging out and implementation from start to finish. It takes more time at the beginning, but it takes so much less time to clean things up later that the additional time cost at the beginning is usually worth it. Writing prose is similar. it might seem like you don't want to waste time outlining and sketching out ideas, but it's usually easier to assemble something useful from an outline than it is to try to work with a disjointed stream of consciousness. You might get to a point of familiarity and/or mastery where you can do a lot of that work in your head. But that's very different from not doing that work at all.