saving

Why is it so hard to save money. As you know I have a job and get paid every Friday. It seems like when every Friday rolls around I have the same amount. Through the week I end up spending money here and there, just a little, but it adds up. Now that I realize I have a problem I am going to try and fix it. I have been trying to save up for a keyboard. My plan of action is as follow: 1-Find the keyboard I want so I know how much to save up. 2- After each paycheck I first will pay tithes then put 50% of whats left in savings for the keyboard. Then put $30 away for gas/ general saving. The rest will be my disposable income. If I see hat this plan is not working then I will change it accordingly.