i don't get it...

I think i really cannot be accountant liao la... Today i went out of house with $50 but i came back with $10... I'm quite confuse le... Where my money go ? I got drop money not? Did anyone of them gave me the wrong change? Alrite this is wad i bot la.. 7 bucks for kfc, 15 for coffee bean, 2 on old chang chang and another 15 bucks is for the steamboat i owe yuki... let's just say it's total of 39 bucks... so i should have 11 in my wallet rite? So how much should be in my wallet in the end? i think is 24 bucks le... cos i spent on coffeebean and yuki's 15 should be around 26 bucks.... so my wallet now shoul have 24 rite? but how come nly have 12???!?!! i think i drop money le... y like that?? did i drop 10 bucks? where did i drop it? omg!!!! y i so confuse? i dun get it le... simple maths i also cannot do... i feel so sick for myself... and i realised after drinkin the lattte i cannot breathe properlu and my heart beat super fast lor... so scary....
ThankGod mr Nic bring me to mcdonalds tonite... i'm so gald....