I’ve had my 13 year old ex racehorse for almost a year now. His previous owner always lunged him before they rode him. We didn’t at the start but he was just too much of a handful. I have been lunging him less and less each time I rode to the point that i tried not lunging him. I was walking him around and I slightly but my inside leg on and boom he bolted, the rest of the lesson went on like this. With school it is getting harder to ride him and lunge him before dark. Can I have any tips to get him out of this habit?