I remember it was easy for me to make a list of favorite artists or movies, but that was when my world was very small — it was just beginning of grade school, so you had maybe a buck of tapes, a tape rental with always same tv-series and movies available, and well, I just didn't experience much at that point.
When world opened I noted how many things there are, and more importantly, how small were I knew. It didn't grow on me instantly, more like a slow flow of exploration — new things, new music, new people which all make previous experience feel kind of small and biased. After some time, going back to things I absolutely loved became a kind of two-sided blade: yes, now I understand them even more clearly, and oh no, they are so different from how I felt about them back in 10 or 20 years ago.
The point is? I think what you feel right now, what you like right now is what makes you up. To me being alive is a fleeting experience, there is no single state that can describe that yes, this is complete me, and tying together memories from different periods of time are all a bit similar but "different" versions of me, for better or worse.
I think I begin to feel that these changes follow some direction over time, perhaps these directions what make me up, but can't say for sure.
P.S. When posed with such question, I usually blurt out lighthearted answer recalling whatever I experienced and liked in past month or so. That is usually close enough to what feels right.