Extreme deep thoughts of my twisted mind.

[Froge]

When the conditions became appropriate, a certain type of matter, an organism, began to appear on our planet which has self-replicating properties (abiogenesis). When replication occurs, there are bound to be mutations. Some mutations allowed an organism to adapt better to the environment, thus causing it to survive longer and replicate more. All our brain's hormones and neurotransmitters that control our thoughts probably came about because they were beneficial to our survival.