As a clock maker I recognise this completely….
Because my first clock was a major undertaking for me, despite having made many things during my life, it required me to make the parts and then store them in plastic bags for several weeks, months and in some cases, a couple of years. When I came to assembly I was fairly horrified when the parts were unpacked….in fact, i could not believe that i had produced such poorly made items! So, my first clock was effectively made about three times as I could not bring myself to fit some of the parts and simply made them again…….FOUR pallet arms!…two spring barrels, numerous extra wheels, three sets of pinions. Then there were the actual failures of skill and knowledge that caused me to keep to this day a small box of the more 'priceless' mess-ups…pieces of brass that were not annealed enough and simply broke,…arbours tempered too hard with broken pivots,…..imprefect small threads and screws,..bent wheels during tooth cutting due to lack of reinforcement….I keep them all and periodically get them out on the bench and peruse my (then) lack of skill…….It helps to track my progress and keeps me humble!
That first clock was a huge struggle and I learned many lessons. Now i always examine all parts thru a strong glass and have my finishing ceremony down to an art, and always make several of most parts so that I get better as time passes and can select the best one…also photograph everything in stages…and keep a notebook…above all, look at the expert work of others and learn great respect.