自动增量重置为0，但不能插入id = 0的值。值> 0不会发生

我偶然发现了一个非常奇怪的行为：

假设我们有一个餐桌顾客：

MariaDB [connections]> describe customers;
+--------------+-------------+------+-----+---------+----------------+
| Field        | Type        | Null | Key | Default | Extra          |
+--------------+-------------+------+-----+---------+----------------+
| customerId   | int(11)     | NO   | PRI | NULL    | auto_increment |
| customerName | varchar(50) | NO   |     | NULL    |                |
+--------------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)

插入几个值：

insert into customers(customerName) values('Foo');
insert into customers(customerName) values('Bar');

然后删除所有内容并重置自动增量：

DELETE FROM customers;
ALTER TABLE customers AUTO_INCREMENT = 0;

现在，插入一个带有customerId = 0的新值：

INSERT INTO customers(customerId,customerName) VALUES(0,'Site owner');

并查看结果：

MariaDB [connections]> select * from customers;
+------------+--------------+
| customerId | customerName |
+------------+--------------+
|          1 | Site owner   |
+------------+--------------+
1 row in set (0.00 sec)

customerId设置为1 ！！！！

重复相同的过程，但重置为5并插入5，一切正常：

MariaDB [connections]> delete from customers;
Query OK, 1 row affected (0.00 sec)

MariaDB [connections]> ALTER TABLE customers AUTO_INCREMENT = 5;
Query OK, 0 rows affected (0.00 sec)               
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [connections]> INSERT INTO customers(customerId,customerName) VALUES(5,'Site owner');
Query OK, 1 row affected (0.00 sec)

MariaDB [connections]> select * from customers;
+------------+--------------+
| customerId | customerName |
+------------+--------------+
|          5 | Site owner   |
+------------+--------------+
1 row in set (0.00 sec)

这里发生了什么？如何插入值“ 0”和插入值？（是的，我以后可以编辑，但是由于种种原因，对于我的情况来说这是不切实际的）。

谢谢！