I come from a big family. I'm talking a family of seven. My parents had five children together and I am the third child of those five. (Yes they are still happily married and us kids did not destroy their lives.) That puts me smack dab in the middle.
Being the middle child isn't always fun. A lot of times you feel isolated by your older siblings but you feel too old to be hanging out with your younger siblings. You can also feel overshadowed by your older siblings' accomplishments and milestones. I mean let's be honest, no one really wants to hear about the 12-year-old who got a 100 on her test when someone else just turned 16 and can drive.
BUT, being the middle child isn't always bad. You kind of get the best of both worlds. You can fly under the radar when necessary but at the same time, eventually, your older siblings move out. Then you're the oldest in the house and it's your turn to get attention for those big milestones.
As I've gotten older, I've also gotten the benefit of getting perspectives from both ends of an age range. I can talk to my younger siblings about a problem and get that carefree teenager advice but I can also talk to my older two siblings about the same problem and get the more mature advice. I can then choose one or a combination of the two to put to use.
I also have built-in friends for whatever mood I'm in. Being a young adult is weird because you're supposed to be growing up but sometimes you still want to be a kid. So, when I feel like being a kid I hang out with my youngest sister and do things like building a Lego mansion when I'm at home and bored. When I feel like being a little more mature I know I can get coffee or dinner with my older siblings and have a more mature conversation.
Another built-in bonus of being the middle child is that you get nieces/nephews pretty early in life, but not too early. I became an aunt at 15 and have since gained two more nieces and have a fourth niece on the way. Being an aunt at 15 is awesome. I got the thrill of having a baby in the family without having to deal with it being a younger sibling. I was also old enough to be entrusted with a little bit of responsibility for the babies but also have a backup caretaker.
Lastly, I get to have in-laws that aren't way older or way younger than me. The two in-laws I currently have are basically older siblings, but better (sorry not sorry). And the two in-laws I'll get when my younger siblings get married will basically just be younger siblings.
Being a middle child can suck sometimes, but as I've gotten older I've come to appreciate the position I hold in my family and I wouldn't have it any other way.