A few years back I worked at a small carpentry company. I was initially hired to help manage work efficiency but then some months down the line I proposed the directors to start doing contracts instead of relying on the same four clients to make ends meet.
The first few contracts I brought were medium-sized projects, producing all wood works for, say, apartment complexes, a couple villas and a public library. Yearly profits skyrocketed, we bought the disused factory next to ours, refurbished it, and hired more people to work on even bigger projects and I even got promoted to assistant general manager.
At the same time all that was happening a friend of mine working at the department of information told me they were going to issue a tender for the restoration of one of the island's forts built by the knights in the 18th century. She offered me the documentation before it was made public.
I jumped at the chance, advised the directors and chose a team of five to inspect the site, and take all measurements. I worked out the materials we needed, the manpower required, etc., a process which took close to a month. Two weeks before the official deadline for submission I had everything we needed and began drafting the proposal.
It was then that I realised my mistake. I had worked on the wrong part of the site and the fort I had made the proposal for was the wrong one. I visited the site again, found the right fort and discovered it was considerably smaller than the one we worked on. We worked 16 hours a day for the next two weeks, even getting a special permit to stay at the site overnight, but we did it. The right project was valued at 750,000 and the wrong one at 2.5mil.
After it was all done I apologised for my mistake and handed in my resignation. I never felt so humiliated in my life. On my own initiative I then contacted the agency responsible for the restoration, told them about my mistake and gave them the proposal for the wrong fort, so should they ever plan to restore that one too, they'd have a complete proposal already.
A year later I receive a phone call from the general manager saying he just learned they got both contracts. He wanted to know whether I was available to help with the projects but I declined since I had opened up my own business in the meantime.