From: SpeedYoshi | #025
One of these is missable, I think its the deku nut one. It's a glitch or something, so do these while you're a kid.
They're both missable. The deku stick upgrade becomes missable once you pull the Master Sword and the deku nut upgrade becomes unavailable after you get the Poacher's Saw.
--
One less bracket.
http://myanimelist.net/profile/tyder21