an embarrassing experience(draft one)

Everyone could have many embarrassing experiences and so do I.The most embarrassing experience I have ever encountered was when I was a junior high school student.One day,I was very thirsty so I bought the beverages in the store.Then, the most embarrassing thing happend. After I have paid the bill, I took my receipt, walk out the store and leaved the beverages and wooden clerk in the store.Fortunately there are no other people in the store or my faced will be as red as monkey bottom I found it until the clerk called me back. From now on, I would remind myself don't made same mistake or it may more embarrassed than that time.Actually, it's not bad to make small mistakes, because it can makes me learning something from it.