From my Mum again:
Sarah's first pony, Smokey, was a great character and a great success. He seemed to have endless energy for long rides and for a while he was a good lead-rein gymkana pony until he tired of that. He did not fancy jumping in the ring either, but I was taken by surprise one day when we were by the local lake, Chasewater, and Sarah told me to watch, then jumped a huge post and rail fence out of the play meadow. That had been practised for in my absence!
We were happy to be out and about having a good gallop over Cannock Chase without being competitive. We were lucky enough to have some good riding country – lots of lanes, Chasewater Park and miles and miles of the Chase. Our only real problem with Smokey came when we acquired a Thoroughbred mare and Smokey suddenly developed a very masculine attitude. Lots of posturing, squealing and stamping. He took the highly desirable Bonnie into the corner of the field and wouldn't let any other horse or pony near her. She was his, and we couldn't take her out of the field without him coming too! Something had to be done, the vet was called and appropriate action taken. I listened to Sarah explaining the situation to a friend of mine using expressions like 'stallion behaviour', 'hormones', 'retained testicle', 'rig', 'cut proud'. She was accurate and concise and about twelve years old. No need for sex education there. She could put two and two together and anything that wasn't clear would be somewhere in a book (Sarah: Eddie Straiton's TV Vet book!)