What the flip's a birthday?

Ruru the Cat here.  I'm not clear what this word "birthday" means, but I keep hearing it.  My people keep talking about that word when it comes to leaving for a few hours, piles of colorful and foreign-smelling things that appear in my house--I think they call them "presents"--and most of all, this yummy-smelling thing I think they call a cake.  I'm not very fond of this word because it means my people are going places without me and eating stuff that smells great that they won't share with me.

                                                            [Behold the face of cruelty.]

Recently, my person's dad held up a piece of this cake stuff.  It smelled so good.  He sang the song on this video.  I kept hearing the words "cat," "birthday," and "cake."  It didn't mean much to me, but what did mean something is he let me lick that delectable stuff.  I thought he was going to let me eat the whole thing, and I was about to go into spasms of joy.  But he gave me about three or four licks--what you see on that video--and then he took it away.  It tasted like milk and something I'm never ever ever allowed to taste.  I think it's called chocolate.  I thought I was going to die with joy.  But then he took it away.

Really?  I mean, REALLY?  I know I'm cute and cuddly and stuff, but do I really deserve this kind of torture?  So many times, the yummy tidbits that are supposed to go to me, the dog steals before I can get more than a sniff.  Much of the time, these human types don't even give me that sniff.  I sit and wait patiently in the kitchen while they make those smells, looking my cutest to beg for a taste.  Then they give me nothing but smells or let the dog have it.  But this was almost worse because I got just enough to tell me I had heaven in my grasp, and they took it away.  Humans are cruel, inhumane creatures.  How do I get one of these birthday things, so they'll give me more cake?