You can tell just by looking, at, say, my last 20 or 30 blogposts, what sort of a mindset I inhabit. Statistically speaking, any rough sample of 30 or more objects will begin to reflect typical tendencies for the group, however disparate.
I like a good art collection because it says something about the person who assembled it, chose it, built it. Beauty is in the eye of the beholder. Many of the great artists collected Japanese prints, African Art, and swapped works with other artists.
If you make or collect art, what does your collection say about you? Is it uniformly consistent, or eclectic? Cave paintings done with fingerpaint, or all black & white photos? Is it planned or ad hoc?