diff --git a/scratch/crash_course_in_python.py b/scratch/crash_course_in_python.py
index 71608d4a..f7238aff 100644
--- a/scratch/crash_course_in_python.py
+++ b/scratch/crash_course_in_python.py
@@ -146,14 +146,14 @@ def full_name(first = "What's-his-name", last = "Something"):
 
 assert x == [-1, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 
-first_three = x[:3]                 # [-1, 1, 2]
+first_three = x[:3]                 # [0, 1, 2]
 three_to_end = x[3:]                # [3, 4, ..., 9]
 one_to_four = x[1:5]                # [1, 2, 3, 4]
 last_three = x[-3:]                 # [7, 8, 9]
 without_first_and_last = x[1:-1]    # [1, 2, ..., 8]
-copy_of_x = x[:]                    # [-1, 1, 2, ..., 9]
+copy_of_x = x[:]                    # [0, 1, 2, ..., 9]
 
-every_third = x[::3]                 # [-1, 3, 6, 9]
+every_third = x[::3]                 # [0, 3, 6, 9]
 five_to_three = x[5:2:-1]            # [5, 4, 3]