Oh... you also need bait, but once you catch/buy your first fish, it is possible to use fish-guts as bait (or any animal guts for that matter), so we don't ask that players add bait to their hooks after the first time. It is assumed that we always keep a little bit for bait for the next catch. Essentially, once you complete the fishing pole and put bait on it, it can be used indefinitely.