The definition of 20 can be interpreted in a variety of ways. In mathematics, 20 is an even natural number that follows 19 and precedes 21. It is composed of two tens, or ten multiplied by itself. This makes it the smallest non-trivial example for the powers of 10; its cube root is roughly 4.641588834 and its square root roughly 4.472135955.

In other contexts, such as time measurement systems like hours and minutes on a clock face or years in calendars, 20 has special significance as well – it generally marks important milestones when counting up from zero (e.g., twenty minutes have passed).

Additionally, certain cultures consider numbers ending with 0 to be especially auspicious; this may explain why many people choose to mark their twentieth birthdays with celebrations larger than those they did for previous ones.

Finally, there are more abstract interpretations which focus on qualities associated with being “twenty”: youthfulness, vitality, new beginnings, etcetera. For instance some might say that being twenty means having enough experience to know what you want out life but not yet so much experience that you feel jaded about things; others might suggest that at this age one should strive towards finding balance between work/responsibilities and leisure activities while still having plenty energy left over for both pursuits!