The phrase "to join the club" means that someone has experienced or feels the same way as others who have gone through a similar situation. Full definition
The latter was the most surprising, given he only joined the club in the summer and had been beginning to impress before falling foul of injury. (justarsenal.com)
This is my first blog assignment since joining the club! (flavormosaic.com)
Instead of eating out, join every club on campus that offers free food, or better yet, start working in the cafeteria or in one of the on - campus restaurants. (thecollegeinvestor.com)