Chuck's First Step
Chuck took his first step due to a combination of physical development and external motivation.

Physical Development
- Chuck's muscles and coordination had been gradually developing since birth.
- He had been practicing standing and balancing with support from furniture or a caregiver.
- His brain had been sending signals to his muscles, preparing them for the action of walking.

External Motivation
- Chuck was motivated by observing others around him walking.
- He may have seen other children or adults walking and wanted to imitate them.
- There may have been a desirable object out of reach that he wanted to reach by walking towards it.

Combination of Factors
- When Chuck felt confident in his physical abilities and motivated by external stimuli, he finally took his first step.
- This momentous occasion marked the beginning of his journey into independent mobility and exploration.