As only John Lennon could put it so clearly, “it will be just like starting over…”
The sense of relief of having landed the new job is palpable. Candidate’s are relieved to have weathered the interview and selection process, and are at times relieved to have landed on their feet professionally and financially. Transitions, either seemless and of your choosing, or dynamic and forced upon you, are stressful evolutions. However, that sense of relief must evaporate before the first day on the new job. Much as graduation ceremonies are referred to as commencement, acceptance of an offer is not the end, but rather the beginning of a journey.
Realization that the hard work is ahead, not behind, is a tough pill to swallow for many. What you did is in the past. It might have been a key component in getting you the new job, but rest assured, it is now squarely all about what you will do going forward. You were hired to perform, not to rest on your laurels.
Starting over is never fun, and it is never easy. There is always uncertainty, possibly some bruising of the ego, and maybe a little crisis of confidence. It will take time to hit your stride, to come up to speed. It will also take work, effort, commitment, and good old fashioned sweat equity. Knowing and accepting that you are starting over is half the battle. Having the energy and will to fight the battle that is starting over is what ensures victory.