Kernel Module exit message get printed next time when inserting the module

I have written simple kernel module to print Hello kernel msg.

my_module.c

#include <linux/module.h>
#include <linux/init.h>

/* Meta Information */
MODULE_LICENSE("GPL");
MODULE_AUTHOR("BHAGWAT");
MODULE_DESCRIPTION("A HELLO WORLD MODULE");

/*this function is called when module is loaded into the kernel*/

static int __init ModuleInit(void)
{
    printk("Hello, kernel!\n");
    return 0;
}

/*this function is called when module is removed from kernel*/
static void __exit ModuleExit(void)
{
    printk("Goodbye, kernel");
}

module_init(ModuleInit);
module_exit(ModuleExit);

Makefile

obj-m += my_module.o

all:
    make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

clean:
    make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

when I insert the module I get msg printed in kernel logs, but when I remove the module msg does not get printed. When I again insert the module, two msg get printed one for last module exit and other for module load. Why module exit msg get printed later when i insert the module but not when removed the module.

bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ sudo insmod my_module.ko
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ dmesg | tail
[   24.595403] rfkill: input handler enabled
[   30.244336] rfkill: input handler disabled
[  145.426767] my_module: module verification failed: signature and/or required key missing - tainting kernel
[  145.427022] Hello, kernel!
[  217.026559] Goodbye, kernel
[  498.489388] Hello, kernel!
[  524.139613] Goodbye, kernel
[  528.270128] Hello, kernel!
[  577.360611] Goodbye, kernel
[  587.700237] Hello, kernel!
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ sudo rmmod my_module 
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ dmesg | tail
[   24.595403] rfkill: input handler enabled
[   30.244336] rfkill: input handler disabled
[  145.426767] my_module: module verification failed: signature and/or required key missing - tainting kernel
[  145.427022] Hello, kernel!
[  217.026559] Goodbye, kernel
[  498.489388] Hello, kernel!
[  524.139613] Goodbye, kernel
[  528.270128] Hello, kernel!
[  577.360611] Goodbye, kernel
[  587.700237] Hello, kernel!
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ sudo insmod my_module.ko
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ dmesg | tail
[  145.426767] my_module: module verification failed: signature and/or required key missing - tainting kernel
[  145.427022] Hello, kernel!
[  217.026559] Goodbye, kernel
[  498.489388] Hello, kernel!
[  524.139613] Goodbye, kernel
[  528.270128] Hello, kernel!
[  577.360611] Goodbye, kernel
[  587.700237] Hello, kernel!
[  667.900373] Goodbye, kernel
[  676.245356] Hello, kernel!
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ sudo rmmod my_module 
bhagwat@bhagwat:~/bhagwatws/Personal/device_driver$ dmesg | tail
[  145.426767] my_module: module verification failed: signature and/or required key missing - tainting kernel
[  145.427022] Hello, kernel!
[  217.026559] Goodbye, kernel
[  498.489388] Hello, kernel!
[  524.139613] Goodbye, kernel
[  528.270128] Hello, kernel!
[  577.360611] Goodbye, kernel
[  587.700237] Hello, kernel!
[  667.900373] Goodbye, kernel
[  676.245356] Hello, kernel!