LYNN – For one morning this weekend, it was hard to differentiate alumni of Lynn’s Brickett Elementary School from the current students.Over coffee and cake, past alumni and employees spun around, pointing at this wall or that wall, touching everything they could and chit-chatting up a storm.”It’s the same,” Lynn resident Betty Roble said. “The nurses’ room is the same, the same creaky floors. The only thing missing is the doll houses on the wall.””Over there was the music room, where my sister played the saxophone for the class, and I laughed and got in trouble,” reminisced Lynnfield resident Jane Booras.”It’s so much smaller than I remember,” said another.The longtime graduates were roaming the school’s halls to celebrate their alma mater’s 100th birthday on Saturday. Founded in 1911 by Leonard Paul Brickett, thousands of Lynn residents have marched single-file through its halls, learned to read and write on its chalkboards and formulated some of the ideas they carry today.Principal Debra Ruggiero said she had wanted to celebrate the school’s centennial birthday after taking over. Everyone who goes through Brickett is part of the school’s family, she said.For Booras, whose entire family attended Brickett back in the 1950s, the day was full of nostalgia.She remembered hunkering down in the basement with her head between her feet for regular nuclear bomb safety drills – “I still had nightmares for years after,” she said – or taping homemade Christmas decorations to the windows.Even some of the founder’s heirs were present. John Bricketts’ great-granddaughter, Doris Kelley Harriman, drove down from New Hampshire to thumb through the old photos and PTA logs. She immediately spotted her aunt in a sepia-colored photo, loading young schoolboys onto a bus.”She was taking them to a Red Sox game – but only the boys in those days,” she said.As Harriman and Brickets’ great-great-granddaughter, Zeanoid Brickett, went off to find alumni who knew her aunt, some of the school’s current students and their parents poured into the entryway.They were there for a celebration and a few speeches to mark the special day.And, as new met old, the school housed them all. Just like it has done for the past 100 years.Amber Parcher can be reached at [email protected].