Half your age...

I woke up last night at like 2am, and for some strange reason I just started thinking about in what year I would be/have been half the age of other people. I don't know why, but out of no where I came up with the math formula to figure it out. I couldn't go back to sleep until I figured it out. I'm not a geek or nerd. I really have no idea why I was compelled to do this, but I guess it is simple enough for most anyone to figure out. I thought you might like to know it.

Oh, and if you still think I am nerdy, you can know it's not true since I didn't write code and create some handy online calculator. I don't even have the ability too.

(x - y) + x = z

x = Year you are born
y = Year the other person was born
z = Year you will be half the other person's age

You math-a-letes can check my work.