Being the President of the United States is difficult for a number of reasons. But one issue you may or may not be aware of are the security-focused limitations on what technology the POTUS can use.When President Obama first came in to office, he was the most tech-forward leader we'd ever had. He didn't just use email (fact: President Clinton was the first to do that in office), Obama used a Blackberry. And on top of being a Blackberry user, he also got to keep on using that phone while in office — a presidential first.Nowadays, large touchscreen iPhones and Android phones are the norm, and the keyboard-wielding Blackberry is an ancient thing of the past. And yet, Obama still uses it.But in last night's episode of The Tonight Show with Jimmy Fallon, President Obama explained the reason why he still doesn't use a modern smartphone.We bet a small part of him can't wait to be out of office so he can use the same phones that his wife and kids already use.