Just started new job as Account Manager in a large corporation. Before starting I got contacted by the biggest real estate company in the contry. They wanted me for interview as a temporary position of head of marketing. Conpleted interview. Went ok. I did not hear from them for a couple of weeks and I like my new job. Stable, okay to good salary opportunities. Amazing coworkers. Thought the chance of landing the job was low and since I hadn't heard from them, I thought the chance was very low of landing the job. So I sent an email stating that I thank them for the opportunity but I just started in a new job. Got a response right away «Oh. That's sad. We wanted to call you in for a second interview fyi. Best of luck in your new job» Who knows what the temporary position of 10-12 months would be, but prospects would be extraordinary good if I had left with a good reference. Have a sinking feeling now that I did the worst career mistake in the century. What is your biggest career mistake?