How hard is the math in the actuary major; does it happen for people to get stuck at a certain level

Hi, I need your help guys to answer this vague question (sorry about that)… I am 32 years old and I came in to the US recently…I just finished the general requirements and I am transferring to a university next year. I am planning to major in a fairly easy subject and go from there… but this last semester, from some reason, I took a trig class, and I have to say that I am finding great pleasure restudying all these stuff (my last math class was in middle school)… To my surprise I am doing really good (I know, it’s just trig)… long story short, I have just found out about actuary, and I was wondering how hard that thing is, and how can I evaluate myself before taking this big step… I am no young and I can’t waste more time… if for example I do fairly well in calc I to III is it a good sign that I won’t stagnate later, or things will get harder for my old brain to grasp?

Thanks