Teacher Spotlight: The Late Mr. Castelyn 

By Noah Shacket 

Charl Castelyn, known as Mr. Castelyn by his beloved students, passed away on November 27, 2023, with his husband Craig Strulovitz and beloved rat terrier by his side.  

Ms. Rusch shared in an email to parents and staff, “Charl was a dedicated math teacher at MS 447 for over 14 years, most of his time nestled in the 6th-grade wing. Over the years of his illness, he always found joy in coming to school. We will remember Charl for his dedication and love of teaching, his sense of adventure, his collegiality, and his ever-present dry humor. His absence leaves us with a great big hole.” 

Beyond his vivacious presence in the MS447 school community, Mr. Castelyn had a vivacious life.  He was born in Durban, South Africa, to Cheryl and Leon Castelyn. He spent all of his time growing up in South Africa until his senior year in high school.  Some of his expressions and word choices revealed his cultural background. 

Mr. Castelyn finished high school in Arizona and finally, in 2004 Mr. Castelyn moved to New York City.  He fell in love with the city and met the love of his life, Craig, according to his memorial notes. They were married in Shelter Island on October 6th, 2012. Then eight years later, he and Craig brought their new rat terrier home. Their rat terrier's name is Odin. Odin joined his daddies on many adventures and has his own puppy Insta. His family loved to travel, both near and far. 

Sixth grade exploration teacher Mr. Dych said “His presence, open mind, humor, and kindness is why I became friends with him. I worked with him for so many years. He's interesting, I always laughed with him. Mr. Castelyn was a true kind man.”

Charl made friends everywhere he went. He saw the good in everyone and was endlessly loyal to his friends, with whom he managed to always keep in touch. 

Ms. Rusch shared in a note to staff and families, “We will always remember Charl for his deep affection for teaching, his sense of curiosity and adventure, his sincere kindness and warmth, his excellent sense of style, and his ever-present deadpan humor. His absence will leave people like his colleagues, co-teachers, and especially his husband, devastated. But their memories with Charl will inspire them all forever.

The turning point in his 10 year fight with brain cancer took a turn for the worst in May of 2023. Regardless of the devastating news, Mr. Castelyn returned to start the school year in September, 2023.   

Ms. Schrup, his 6th grade math co-teacher, shared on his GoFundMe that “he chose to be with his students while persevering through some of the hardest times in his life. When I told our students that Mr. Castelyn was sick and wouldn’t be returning for a while, they came up with all sorts of ideas to help support him. Making him cards and posters, sending him his favorite candy, and one student even asked if they could make a GoFundMe for him. These are new students who have only known him for less than two months. It’s a true testament to the impact that Charl has had on so many people. Over the last 19 years of teaching, he has touched the lives of hundreds of students.”

7th grade math teacher Ms. Wilson said “One of my best memories with Mr. Castelyn is when we went to Atlanta for a math conference. We spent three days talking and thinking about sixth-grade math. We love math so much and working with him for years was my highlight. Teaching with him will forever change my life.”