For some reason my uality just seems like something I'd do as an adolescent but it's not practical later on?

Like I could see myself dating other guys in the next few years. But for some reason i have this image that being 50 and gay would be really perverse. And well idk it just kinda freaks me out. Is that just becsuse I'm so young and I haven't gotten to that age? (I'm 18) like I just see elderly gay couples weirdly for some reason. I really can't explain why. And I would love this to not be the case haha. Any advice?