Python - Why is the first enumerated value (0) not in the list?

Question

zzz = [1,2,3,4]
for i in enumerate(zzz):
if i[0] in zzz:
print(i[0])

Outputs:
1
2
3

In the for loop, item i is:
(0, 1) <--- why is the 0 for i[0] NOT in zzz?
(1, 2)
(2, 3)
(3, 4)

Why is " if i[0] in zzz " true only when i[0] is 1, 2, 3 and NOT when i[0] is 0?

Answer 1

indexes are: 0,1,2,3 values are 1,2,3,4.
the indexes contained in list zzz are 1,2,3. zero is not incuded