I started seeing a man 16 years my senior when I was 18. I thought he saw something special in me, what he really saw was someone he could mould to his way of thinking.
He subtly encouraged me not to see friends or family. He controlled all the money, and wouldn't hear of me working for around 7 years of our 13 year relationship. He used to say things like "You can never be away from me, you will always come back". He used to alter all the clocks in the house, so I wouldn't know what the time was, and (I learned afterwards) would put tranquillisers in my food. He would monitor my mail and generally gave me no privacy, whilst also behaving appalingly himself, taking drugs, staying out all night, gambling etc. He once put three months rent money into a bandit and lost the lot.
I got to 31 and realised one day, that I had grown up and wanted a different life, whilst he had never changed. When we split up, I went through 6 months of hell, with him at one point holding a knife to his abdomen and threatening to kill himself, amongst other tactics to get me to stay. I have never gone back, and now live the life I want. I was young and stupid, but he was very convincing. I have never regretted splitting up with him.