Based on my observation.
I had a bus driver who took ASL classes for four years. She was very rusty. I was partially shocked when she told me she took ASL for four years. She had to pause between many signs to remember better.
I recently met a student who is trying to become an ASL interpreter and has taken ASL classes for 2 years. She is rusty but has wide variety of vocabulary. I told her about silent supper events that we have in the area. After attending several silent suppers, her fluidity greatly improved!
I have a friend who only knew signed alphabet, I started taking him with me to deaf friends, hang outs, silent suppers and so on. He became very fluent and smooth that other deaf people thinks he is deaf. This is just under a year. When I was in deaf high school, there was a student who just lost his hearing from an accident. He knew ZERO signs. End of the year, he was pretty fluent - more than some of the experienced interpreters I know.
In high school I took ASL for easy credit. The teacher has been teaching ASL for 14 years. She is EXTREMELY rusty! She barely could understand me when I was signing at a normal pace. I had to slow down. She never socialized with deaf people.
Socializing is the key.
If I were to learn ASL. I'd feel traumatized, no doubt. A friend or a mentor surely will be helpful! Get one of those first, of course.
