I don't know if this is true for commercially grown avocados or not, but I know it is from some other fruits and vegetables. IF you bought the original avocado from the store you probably won't be able to get a decent tree out of it. The parent trees used in commercial groves and orchards are specifically bred to produce lots of fruits, not to grow another tree. Alot of the food we buy at the grocery store nowadays is tinkered with genetically to suit the needs of the commercial farmer/harvester.
I don't know if that ^^^ makes alot of sense, brain still muddled from lack of nicotine, so I'll use another example. If you wanted to grow a potato patch and started with a potato that you bought at the store, you're likely to have poor results. The potatoes at the store come from plants designed to produce potatos, not more potato plants. To grow potatoes you would need seed potatoes, available from feed & seed stores. Also, some of the fruits and vegetables in the store are treated after picking to retard growth, so they have a longer shelf life.
