Ah, that one is rather easy! A perfect day for me would be one full of progress in my research. I like to feel like my day was productive in some way, so it is especially rewarding when I finish a day having completed everything I had set out to do that morning.

[As enthusiastic as he sounded at first, it fades a little as he comes back to reality.]

Of course, I haven't been able to work on my research at all since arriving here, so I've been forced to try to find productivity elsewhere.