Why Do We Collect Things?

Homo sapiens, I mean we, have been collecting since forever (since we were hunters-gatherers during our evolution, say the psychologists). Some of us have evolved into 'hoarders' (there seems to be a problem there), some into sophisticated 'collectors' (whose valuable hoards/collections may be wealth generating or may even be the basis of new museums/institutions), and then there is the rest of us who may have sentiments and/or temporary obsessions over certain things.

Anyway from the myriads of reasons why we collect as we do, here are some by the experts:
1. To learn and acquire knowledge because of interest in the topic (thing?)
2. For fun and pleasure; to satisfy a sense of personal aesthetics and please personal tastes
3. To recollect memories of childhood, travel or history; to relive the past
4. For control and achievement; to show individualism and to be complete (something to do with wish fulfillment which eases deep-rooted uncertainties and other psychological mumbo jumbo ...)
5. For no rhyme or reason; just for some unexplainable 'magic' in our lives.

I do not have any valuable collections that I could bequeath a library or museum but the children can inherit some things from my temporary obsessions with crystal bracelets, charm bracelets, dragonfly brooches, and shawls. (I can almost hear them say, "Mama, thank you, but may we sell them off to Cash Converters?"). These I collected for reason no. 2, I think, except dragonflies fall under no. 5 - Magic!

My book, music and movie collections are too eclectic (and too few?) to be of importance. Again no. 2 and no.1 seems to be the reasons why they were collected. My family photo collection calls for reason no. 3 mostly. And then there are the tacky/kitschy souvenir collections of fridge magnets, snow globes, china plates, photo frames, etc., etc. ("Can we please have a garage sale, Mama?"). Reason no. 3 again, although snow globes are 'magic'.

Hmm... Reason no. 4 does not seem to appear as to why I collect, I wonder why? Do I not want to control and achieve, to show individualism and to be complete? Now, what can I collect to fulfill all of reason no. 4? What wish fulfillment do I have to ease deep-rooted uncertainties and other psychological mumbo jumbo? But then again, I guess no. 4 may be the underlying reason why we all need to collect/hoard in the first place.