I respectfully disagree. We cannot control our feeling (being offended or not). What we can and should control, however, is the decision of what to do with this feeling of being offended. Some of us may be offended by merely the presence of loud liberals in our neighborhood. Doesn't mean we do something or whine about them, like these people do.
I think we can develop the emotional maturity to not be offended at things where no offense is intended. Maybe lacking emotional maturity one would not be able to control emotions. But in chosing to develop one’s emotional maturity they learn when there is truly offense meant and when there’s not. They’d also learn the difference between being excluded by others from an activity like Christmas and one chosing to exclude themselves-—and then not being offended when others chose to partake. So you are partially right—we don’t control our emotions or those things at which we take offense until we develop the capacity to not misinterpret events as being a personal affront. This is a skill that takes a long time to develop. It’s one my company, in part, trains with business managers and their employees and we see it is a learnable skill.