Synapses can build without neurochemicals, but it takes a lot of repetition. For example, you can learn romantic words in a foreign language quite quickly, but learning verb conjugations usually requires dreary repetition. Romance triggers neurochemicals that build synapses quickly, but repetition gives you the power to build any synapse you decide is important. If a synapse is activated many times, it gradually learns to transmit an electrochemical signal efficiently, even without extra rowboats in the fleet.
