I joined a section of the Girl Guides when I was in my penultimate year at school. It was a complex decision. My Headmistress thought I was a bad lot because I was an atheist but wanted the kudos from any academic success I might achieve. I felt that I had been treated very hypocritically by the PTB at the school, so was prepared to fight hypocrisy with hypocrisy.
I needed a good report from the Head in order to get into university so I decided to appear to be a good member of the school. I started doing all sorts of pointless activities for my school house and I joined the school company of Guide Cadets (they were a division of the Rangers who were supposed to be training as Guiders). This involved doing all the stupid camping and stuff and divising games for Brownies.
In order to get into the Guides I had to swear to do my duty to God and the Queen. So I swallowed hard and said it.
All this activity had the desired effect: the Head thought that I had matured wonderfully.
As soon as I got into my preferred Oxford college, I left the Guides.