Are you the same person you were a decade or three back?
Some people do settle into a comfort zone and lock themselves in--entire countries do this--while others are always looking for new experiences, new stories, new themes.
Every person is going to be different, I think.
FWIW: Me, sometimes my perception changes, sometimes not: some books I reread every few years and they still amuse or impress me as much as they ever did--others not so much.
Edgar Rice Burroughs' THE RIDER is a trifle and generally deprecated within his body of work, but for me it is endlessly diverting. And I keep coming back to it when I need a fluffy but amusing delight.
Conversely, the first time I ran into Tolkien I read the four volumes twice, back to back. In a week. (Not much sleep but it was summer anyway.) Five years later (after a lot more fantasy: from Fritz Lieber to Brian Daley, Stephen Donaldson, and Piers Anthony) I went back and it was a drudge. The world was still engrossing but the prose felt overblown and ponderous compared to other practitioners of the genre. A decade later I tried again and it wasn't as bad but not quite as magical as the first time. Familiarity bred... impatience.
I've learned that I favor storytelling over craftmanship; I will reread Doc Smith more readily than Harlan Ellison though I appreciate and accept both as very different poles of the infinitely mutable genre I love. Just as I've learned to appreciate the samples I run in my forays into other genres and fields.
For me reading is as much an education as an exploration and I *hope* my perceptions change over time. I'm not old enough to settle into comfortable old-foggy-hood.
