When we refer to 'the first year of life', we mean the time from birth until you turn 1.
Similarly, you'd say something like 'you're a child in the first decade of your life and slowly start to mature into a young adult by the end of the second decade', referring to 0-9 and 10-19, respectively.
No, we don't.
When we refer to 'the first year of life', we mean the time from birth until you turn 1.
Similarly, you'd say something like 'you're a child in the first decade of your life and slowly start to mature into a young adult by the end of the second decade', referring to 0-9 and 10-19, respectively.