I don't know you or where you're from, but that's unheard of inside the circle of people I know.
Not really a fair question, given the taboo still surrounding the drug. Imagine asking a homosexual in the 1950's "Are you proud to be gay in the context of everyday society?" Of course the answer is going to be "No." But in certain circles - namely those that don't give in to the notion that such experiences are unspeakable - the answer is surely "Yes."
That said, I agree with zafka that being "proud" to have taken LSD is effectively a category error.
Two points:
First, the concept of LSD user is misguided. In soviet Russia LSD uses you. Second, the world is larger.