Dàxué sì nián shì wǒmen zuì nánwàng de zhēngróngsuìyuè.
The four years of college were the most unforgettable, formative years of our lives.
Tips
usage
Reverent and nostalgic tone — usually reserved for wartime, revolutionary, or other formative and dramatic periods. Don't apply to ordinary stretches of time.
memory
峥嵘 originally described towering, craggy peaks; applied to 岁月 (time), the image is of years that rise sharply and leave a mark — not flat or unremarkable.