It is, in my opinion, entirely probable that this first stage of collecting results from the hunting instinct. An assortment of corroded old cartridges in a jam tin under the bench in the garage, for example, bears little resemblance to the same items when cleaned, catalogued, and neatly labelled on a display board. One is potentially dangerous junk, while the other is a work of art. This too, continues to have some practical relevance. In some collectors' minds, the investment value is obviously a large part of the whole thing.
Some collectors seem to love the 'horse trading' more than the collection itself.
Collections may have serious utility value also. Consider the collections of firearms in forensic or other museums. Collecting forms an important part of knowing. Significantly, collecting is acknowledged as a permissible purpose for owning firearms under the revised laws of most jurisdictions in this country. Unfortunately, however, the bureaucratic processes have not yet digested the full significance of this, and as a consequence, many fine, harmless and irreplaceable old firearms have been needlessly destroyed.