After a four-day weekend it's not easy to get your brain back in gear for the work week. So consider this two-and-a-half minute collection of optical illusions a mental boot camp with Richard Wiseman serving as your overly-pleasant drill sergeant.

Admittedly, some of these illusions are a little old. In fact, there's a good chance your grandparent's grandparents were befuddled by the rabbit/duck illustration. But there are still plenty of newer illusions that will leave your wondering why the human brain can be so easily fooled. [YouTube]