I always forget the lifecycle of custom server control classes with respect to web page, ie. aspx file.

The following results are based on a drop down list custom control:

customcontrol - Constructor
customcontrol - OnInit - Enter
customcontrol - OnInit - Exit
webpage - OnInit - Enter
webpage - OnInit - Exit
webpage - Page_Load - Enter
    customcontrol - could be altered here in page load, causing some event to fire
webpage - Page_Load - Exit
customcontrol - OnLoad - Enter
customcontrol - OnLoad - Exit

POSTBACK:

customcontrol - Constructor
customcontrol - OnInit - Enter
customcontrol - OnInit - Exit
webpage - OnInit - Enter
webpage - OnInit - Exit
customcontrol - LoadViewState - Enter
customcontrol - LoadViewState - Exit
webpage - Page_Load - Enter
webpage - Page_Load - Exit
customcontrol - OnLoad - Enter
customcontrol - OnLoad - Exit

customcontrol - OnSelectedIndexChanged - Enter
    webpage - xx_SelectedIndexChanged - Enter
        customcontrol - could be altered here in page load, causing some event to fire
    webpage - xx_SelectedIndexChanged - Exit
customcontrol - OnSelectedIndexChanged - Exit