Ringing inside my head...

Dont know why but this song always ringing in my head, make me uncontrolably humming, just like that... and even I played this song automatically with my guitar....

I wanna make you smile, whenever you're sad,
carry around when your athritis is bad,
all I wanna do, is grow old with you...
I'll get you medicine, when your tummy aches,
build a fire when the furnace breaks,
oh it could be so nice, to grow old with you...
I'll miss you..., kiss you...,
give you my coat when you are cold,
need you..., feed you...,
even let you hold, the remote control...
so let me do the dishes, in our kitchen sink,
put you to bed when you had too much to drink,
I could be a man who grows old with you...
I wanna grow old with you...

Gaahhh... I think I'm going nuts