Question about premonitions

I always knew I was special since I was younger but it was never until a few years ago that I started picking up on certain things. I can distinctly remember talking to a ghost once when we moved into our new house. My uncle had died in the same room I was in and I knew I was being watched. Moving on to the real issue, I recieve premonitions. I used to get them constantly and they were usually accompanied with a feeling of dejavu. I was at a convention in St. Louis once and I was standing in the hallway waiting for the elevator. I saw this man and this woman stop and start talking. Immediately, I thought about him getting on one knee proposing. Thinking that would be weird, I noticed that he got on one knee and proposed. It freaked me out because I had never had a premonition before that was that vivid, that accurate.

Problem is, theyve stopped. I used to have them every now and then but now, nothing. So my question to you all is in a few parts:

1. How do I "re-activate" my ability?

2. How do I distinguish between a premonition and a thought?

3. How do I learn to control my premonitions so that I can get one when I need it? For example, if I knew my grandmother was in the hospital. How would I be able to get into the ability to give me a glimpse as to whats going to happen?

Try meditation. Shambhala meditation centers hold meetings once a week on Tuesday in almost every city. They will teach anyone to meditate free of charge.