The Ender 3 arrived as a flat box of aluminium extrusions and a bag of bolts, and four hours later I had a printer and a deep new respect for whoever wrote the assembly instructions, because it certainly wasn't the person who printed the manual that came in the box. First print was the obligatory little boat. It came out looking like it had been retrieved from a shipwreck.
The failures so far have all been mine, which is somehow both annoying and reassuring. First lesson: bed levelling is not a one-time setup, it's a ritual you perform with a sheet of paper and a great deal of swearing every few prints. Second lesson: the first layer is everything. Get that wrong and the rest is just decorating a mistake. I've had prints peel off the bed mid-job, prints turn into a bird's nest of stringing, and one memorable attempt where the filament stopped feeding and the nozzle politely drew air for an hour.
What's surprised me is how much I'm enjoying the feedback loop. It's the most physical debugging I've done in years. You change one variable, temperature, bed height, print speed, and you get a tangible artefact back that's either better or worse. No stack trace, no flaky test, just a small plastic object telling you plainly whether you got it right. The boat is still ugly. The next one will be slightly less ugly. That'll do for a Sunday.