Second language dream

I wonder whether I can recover and expand the Spanish I learned over four years in high school, a quarter century later? I never became fluent, though I always wished to, but since I live in California the opportunities to use the language are ever-present. I have retained the exoskeleton of the language, meaning vocabulary and some verb tenses are automatic in my mind, but there are huge, gaping holes I would have to fill. Is it too late?