Hi, I have one begginer question. It is may be simple, but it very baffles me. I am reading Pharo by Example (great book btw, thanks!). I'm in chapter two where I'm creating Lights Out game. There is this simple code http://pastebin.com/eQregZ35. What baffles me is line 10. I assign "Block of code" to mouseAction variable of LOCell. In this Block, there is "self", that obviously refers to LOGame object in that time. But when is this Block actualy EVALUATED (when I click on Cell), "self" should be reffering to LOCell object, isn't it? If I inspect one LOCell, inspector shows that it has instance variable "mouseAction", which is BlockClosure, that looks like "[self toggleNeighboursOfCellAt: i at: j]". If "LOCell" is the "owner" of this block and also it is the one that evaluates it, shouldn't "self" refer to LOCell object? How BlockClosure desides where "self" actually points? Thanks for explanation. Jan