It is easy to forget that Chamorros have been in Guam and the Marianas in one form or another for close to 4,000 years. Magellan only arrived close to 500 years ago. The period of colonization that we still live in today is only around 350 years old. In all this time Magellan and his presence on Guam amounts to two days, during which time he killed several Chamorros and burned a village. Magellan may have been the one to put Guam "on the map" in a literal sense, in terms of Magellan being the one who for the first time identified land in the Pacific Ocean for Europeans. But this shouldn't extend much further, and certainly not be the type of thing where people should feel a historical debt. To claim that Magellan is the most important person in Guam's history basically boils down to making an argument that the rest of the world and how they see the world and understand history is more important in understanding Guam than anything that you might imagine comes from Guam.
The term discovery is one I have discussed plenty of times on this blog. It is such an empowering concept, at least for those who claim to be doing the discovering. For them the term has a way of creating new beginning, like a new map being laid over the earth, and once its corner all lie flat, you have ascended into a new, higher position because of the cartography of that map. For those who are the "object" of something that is discovered, the concept of discovery pretty much sucks. It means that all your claims to said thing are erased and superseded and twisted in previously unbelievable ways. "Discovery" has way of making the things that are clear, visible and obvious someone appear to be the opposite as a new type of normal comes into play. How could you really claim to be "discovering" anything if people were already there? In truth, in the terms that the term should apply, your claim is secondary at best, but certainly couldn't claim to be anything serious. You may have found something and "discovered" if for yourself, but how could you really claim to have discovered anything? Well you can so long as you find ways of weakening the claims of others. You have to argue that they didn't really live there, but were like nomads. That "owning" something is a modern idea and so even if they did live there they certainly couldn't really claim to have done anything than inhabit the air above the land. Finally, even if they did live there, the land was wasted by these primitives who can't really be claimed to discover it since they could not make use of it in a modern and appropriate way.
What is truly unfortunate is the way that Chamorros have eventually come to accept the basic discursive formation to built Magellan's discovery claim. It is not so much an idea that is constantly being enforced by outsiders, but something that Chamorros have taken on the task of perpetuating.
They have come to feel like they could not exist without Magellan, as if their place in history would not exist without him. One form of evidence that I use to point this out is the monument built in 1926 in the village of Umatac, where Magellan was reported to landed in 1521. The monument was built by the Guam Teachers Association, which consisted of both Chamorros and non-Chamorros. This was one of the first monuments that Chamorros every created for themselves in contemporary context, and they decided to commemorate someone else.
It is important to remind ourselves that we existed long before Magellan, and even if he had died in the Pacific and never heard from again, we would still have existed.