"One time, I had to decide on a budget for a project that had a lot of unknown variables, and I wasn't sure how we'd proceed while reaching the internal milestones. It was a unique environmental project that we had never worked on before, and I could not use historical data to forecast expenses. We needed a budget in place to start the project. I did some research, ran some numbers, and eventually came up with the rough number. It was approved by the management team, and we started the work. In the end, we didn't have enough funds and had to extend the budget. Needless to say, my superiors weren't happy about it, but what could we do? I learned my lesson, and from then on, I made more accurate budget estimations by adding 10% for undetermined tasks, client requests, and interruptions in the schedule."