As the picture describes, forgetting your ID means you will have no future. What does bringing your ID to school or work have to do with having a future? And is that sign even real?
The sign's message has to do with the basics in life. Some of the most basic things you do as a kid, which you must remember to do everyday is to bring your backpack and your school ID. If you went to school in Asia, the school ID and uniform was a normal practice of life. For 99% of the kids in school, they religiously bring their IDs and never forget.
However, there are those few who forget their IDs consistently enough that it becomes a habit. When that forgetting your ID becomes a habit, you have no future.
What is going to happen is one day, you will forget your ID on the day that you have to pay tuition at school. So what if you forgot your ID? Well, you're going to need to identify your school to the guard at school as well as the administrator collecting your tuition. Because you've failed to pay your tuition at an earlier date, you're now paying it on the last possible day its due and now you can't because you forgot your ID.
Since you didn't pay tuition for the semester that was over, you're not allowed to take finals and all of your classes have no grades and you essentially fall one semester behind your former classmates.
They are former classmates now because they are graduating one year before you do. But you've become so depressed that you lost all your friends to graduation that you forget about school and dropout all together.
As a dropout, you end up on the streets of Berkeley, begging for food and money. You have no job because you have no skills and no work ethic. With no job, you have no future beyond the streets.
The reality is that description above is some of your friends - it might even be you. Life requires the ability to do certain fundamental skills consistently, such as remembering to bring your ID to school.
It's a lesson to teach to your friends and to your kids. Remember the most basic things in life and you'll be okay - people's birthdays, your wedding anniversary, and most importantly remembering to bring your ID wherever you are.