Assets is the plural of asset, right? Well, yes, but that was not always the case.
Assets us one of the many English words that came from the French language after the Norman conquest of England in 1066. The French word was asez or asetz, meaning "enough." It was a legal term that meant, in effect, that a deceased person left behind enough property to bother dispersing to survivors according to the terms of a will, if any. The modern French word is assez, which like the earlier words is singular.
The English spelled it assets, which was also considered singular. In English, it looked plural, however, so naturally people began thinking of it as plural, using it with plural verbs. And then somebody created a new singular word - asset. Thus, a wooden chair left behind by a dead man was an asset, while his bed and chair were assets.
Today we speak also about the assets of living people - their intelligence, sense of humor, sweet smile, etc. - but the word continues to be used in estate law as it has for hundreds of years.
And that's about enough. One of the assets of this blog is brevity.