system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does an avocado develop nutritional fat in it, while most every other fruit has zero fat?

See title. I can't think of any other fruits with fat in them, or at least a significant amount. What makes the avocado special and how does it do that.
gpt
An average avocado contains 6.7 mg if monounsaturated fatty acids. All plants contain the instructions to make these, but avocados are unique to produce these in the fruit instead of the starch and fiber most plants use to make their fruit edible. (Yes, edible is the goal. Edible fruit means that animals poop out the seeds and distribute the seedlings.) 

Avocados belong to a genus of plants called persea, which use fatty acids in their leaves, stems, and seeds to repel water in wet environments and to help survive in hot conditions. Avocados are one of the only species that had figured out that these can be used to make edible fruit.