Something that applies when you get a little older - if you’re in a relatively specific job field, don’t burn your bridges at a job you’re going to leave. You never know who will be sitting across the table from you at the interview, at the meeting table, on the job site. People in the same field tend to move around in the same jobs as you. If it’s someone you burned, you may not get the job, or if you do, it could be pretty miserable.