My older sister and I were brought up believing in santa, and I loved it
Although honestly, it totally weirded me out that a stranger came into my house in the middle of the night.
With my younger sister I was the one wrapping presents, hiding them under the tree, and playing along. That was a test in patience, let me tell you. She always had a bunch of presents from Santa and my older sister and I just had a couple small things because my mom is poor and my little sister was the only one who believed in Santa.
Every year she'd make a big deal about how she got so many presents and we didn't neener neener! Holy cow did I ever want to just shake her and be like "NO! That's not how it worked, we didn't get presents because MOM spent all her Christmas money on you, ya TWERP!" It's pretty much a miracle that that never happened, lol.