Lyric discussion by RedTreeClearance 

Cover art for Dimmer lyrics by Bishop Allen

zedong82-

"Olly olly oxen free" is something that kids say while playing Hide-and-Seek in the US. The person who has to find the others has to close his eyes and count (usually to 100). When he's done counting, he shouts out loud, "Olly olly oxen free!" to warn the people that he's ready to search and find them.

My guess is that for this song, the narrator is saying this phrase to mean that he isn't going to just sit there and count anymore, he's going to get out there and make something of himself. He'll find ways to be noticed/seen.