I don't know anything about prostrate cancer or the scan, but I would say far from becoming complacent, I think after having one cancer, you are more likely to become very aware of others. I know when I had some symptoms of bowel cancer last summer, I freaked, partly because um, possibility, no matter how small, of cancer, partly because of the delay in getting a colonoscopy as hackers messed up our health service in Ireland and delayed everything, largely because I had just gotten a permanent contract at work and didn't want things to be messed up, but also because small as the chance was, the chance of thyroid cancer had also been small and that had come true and a lot of what the doctors were saying - "you're at very low risk, but we need to rule it out" - was very  similar to what they'd said before I was diagnosed with thyroid cancer.

I doubt you are at risk of becoming complacent. Once you have cancer, it sort of becomes real to you and you get way less complacent of or oblivious to it than you were before. It's possible to get too aware of it, because most things are not cancer.