For me, perhaps things are a bit different from most because I'm older, and quite independent, and also past the age where I would still have any kind of peer pressure. I'm a singer and guitar player, and while I've largely retired from (at least trying to) making a living through music I often go out to small venues where I do like 15 minute slots simply for the pure joy of it, and those in the audience who know me might assume they will hear at least one Katy Perry song on a night when I've turned up. And that's true, I haven't done a set until Katy has made an appearance, even if in one and a half octaves only, as I couldn't cope with singing her full range note by note
Haha, I might not go like 'omg, I love Katy Perry', but e.g. when I walk into my local supermarket and a Katy track is playing it's quite normal for me to kind of dance from one aisle to the next and sing along with it
also, I'm in such a fantastic mood then that I'm much more extra friendly to the staff at the checkout etc, it has its desirable effects on my environment, haha!
My friends, the imaginary ones as well as those few others, all know that I'm a fan in spite of my age - but then it isn't so totally odd for them (yes, for those few others in particular) because I've been an active music guy always, and they're always fans of somebody or something musical for their whole life. Most people I know have posters of Bob Dylan or some folk band at home, my Prism and TD posters may be a bit different but they're not sooo out of this world either, haha
I did read about KatyCats who look for Katy Tshjrts without her face on them, but I wear preferably the one now I got in one of the arenas with the Prism portrait of hers, know which one I mean? Again, I'm just past the age now to feel such shyness about it
People usually talk to me about music in general but then also about Katy Perry, and I mostly answer a couple of questions they might have about her but then try changing the conversation by asking them about something completely different, so in my environment I don't really have the problem of perhaps being too much in their face about my 'obsession', haha, on the contrary I want to convey the message to them - 'it's okay, we can talk about something else now, tell me what news you've got!'
I couldn't say that I wouldn't be here without Katy because the worst things in life all happened before Katy Perry, but as she does motivate me a lot concerning many things, and make my life better and much more beautiful I openly say so if that occasion arises, it isn't like somebody mentioned a keyword and I'd go on about it forever, but simply saying how things are for me,
My fan thing is a bit different maybe, I keep searching YouTube for videos of the warped tour times etc and spend the night working out Katy's original guitar parts to her old songs, I would guess most KatyCats won't be doing that and for me it's the most important thing in order to 'connect' with her, and of course, as a straight man I do see a lot the actual woman Katy in Katy Perry, and I can always be open about that, it doesn't seem strange to people hahaha!