Birthday Tammy Logic

Last night in bed my husband and I had the following conversation about my birthday.

Xander: Happy Almost Birthday!!
Me: *Sigh*  Only a half hour left of my youth…
Xander: Oh the daaaah-RAHMAAA!!
Me: It’s true.  Tomorrow I’ll be 34, and do you know what that means?  Next year I’ll be 35!
Xander: All that and you can count too?  I’m so lucky…
Me: No, seriously, 35 sounds so much older than 34.  When you were 19, didn’t 35 sound absolutely ancient?  As long as I’m not 35 I haven’t really felt old.
Xander: Wait a minute, I will be 35 this year!!  Thanks!
Me: *ignoring him* Then, do you know what comes after 35? 36!  Once I hit 36 I’m on the way to 40! *Starting to feel weepy*
Xander: I hate to break it to you, but you are heading for 40 now.
Me: *Shockhorror*  I MOST CERTAINLY AM NOT!!!!!
Xander:  Um, yes you are.  If you are heading for 35, you are also heading for 40.
Me:  NO. I. AM. NOT.  I am heading to 35, not 40, 35.  Once I’m 36 I’ll be heading to 40 but right now I am heading to 35.  Do you hear me?   You are wrong.
Xander: I’m getting the feeling this is another one of those Tammy Logic things…
Me:  No, it’s a fact. Right now I am heading up a hill towards 35. *Upward motion with hand*  Once I turn 35 I’ll be at the top.  Then once I turn 36 I’ll be on my dooooowwwwn towards 40.  So right now I am not heading towards 40, I’m heading towards 35.  You see?  So when I turn 36 I will be heading to 40.  Not 45, 40.  Cuz when I get to the bottom I will go uphill again when I am heading to 45, which won’t be 50, it will be 45.  Do you see now?  *Breathlessly making up and down motion with hands*  UP, Down, UP, Down.
Xander:  Umm, yes.  You are still heading for 40 though.
Me:  *Silent while wondering if I could kill him and get out of the country before they catch me*  Iamnot.  *mutters*

I dunno, it makes perfect sense to me.  Clearly, he is wrong.