The beginings of medicine

So I'm currently in week 2 of a 12 week process, or what we call medicine rotation. I am following 3 patients, we're currently on call Q 5, meaning every 5 nights we're on overnight call, and my residents are fantastic--they teach, they're friendly, and I wouldn't mind hanging out with them outside of the hospital. But when people ask me "how was your day?" a response hasn't really jumped out at me. I guess I'm just sort of blah. I feel like I am going through the motions. I'm not bored at work. I am tired. My patients are interesting. I enjoy figuring out what is wrong with them. But then...well...I am kind of over it. So living every day is just a way to get to the next. It sounds terrible. Like I'm having a horrible time, which is definitely not the case--I have been laughing all the time at work, but I think I need something else to spark the situation. It hasn't happened yet.