Oddness?

:dunno: so bought a board from someone today…the boots are… K2 Raider BOA Coiler Snowboard Boots 2009 : Snowboard Boots | evo outlet but they are a size 13…..my shoe size is a 10…i said what the hell put the boots on tightened em up and they fit….my feet dont move inside the boot or have any play its oddness i tell you oddness y is this