Is it “sad” to go to a concert by yourself?

I’ve recently started doing more things by myself like going to the movies or camping. I’m going to a concert soon that no one in my friend group has time for. And I was wondering if, from the outside, it looks kind of sad to see a woman in her thirties having fun by herself. I was even thinking of getting a year pass to an amusement park just so I can go whenever I want. I have friends and family. Even a boyfriend(he works a lot). But everyone’s at that age where they have bigger responsibilities to handle. I don’t have kids to take care of or school anymore. My job is stable enough where I have enough wiggle room of time to go out and enjoy life. I don’t feel sad or lonely. I’m having fun. Just by myself.