The first day is like the 9th day is like the 43rd day is like the 762nd day in one sense, as the places and the some of the people are the same. Of course, it’s you every day, so . . .
But in another sense the first day presents opportunities and liabilities both symbolic and practical. The advantage you have on the first day is fresh energy, optimism, and a clean slate with people. The disadvantage? You know practically nothing and have given no one a reason to think you’re worth their trust.
A mentor told me on my last first day, “Begin as you intend to continue.” I took that to mean that the attempt to bowl people over with your ideas and energy at the starting gate will backfire once you begin to lag, which you surely will. So be mindful of the temptation to create unsustainable expectations.
But create some expectations on the first day, even if only of yourself. Crack a joke. Take a breather. Do something without being asked.
Worry less about impressing new people and more about impressing the person who has been through all your first days and who will endure the highs and lows of all the days after this: you.