Selector command in tellraw command does not work
Your syntax is incorrect; you had not closed the current object before opening a new one within the array (causing a syntax error due to an object being opened without a name).
"text":"[", { selector
As of 1.9, JSON input must be strict, in that quotes must surround key names and string values. Your selector tag was missing quotation marks around the key.
Fixed command:
/tellraw @p ["",{"text":"["},{"selector":"@p"},"]",{"text":" Woah, this is wierd.","color":"gold"}]