I understand about 90% of the patois (whicch I learned back in the 80's by total immersion in about six months with all of my JA friends talking to me only in patois so I could learn it. The only time I speak it is when talking to very old Jamaicans in their 80's and 90's who might not understand my english (or when I get really angry LOL). I used to talk patois to young children, but I was asked by their parents to speak proper english to them so the kids could learn and practice english.

I do find that when I have been away from JA for several years, it does take a while to start understanding it correctly again. Quite a few of jamaican sayings cannot be taken literally - reminds me of parables.