Emergency services had been called to the estate after the accident and the princess was taken to Southmead Hospital in Bristol.
She had to temporarily step down from royal duties while she recovered, missing a planned trip to Canada and the Japanese state visit to the UK.
Princess Anne commented on realising she might have had a near miss with more serious problems.
“You’re jolly lucky… if you can continue to be more or less compos mentis [of sound mind] and last summer I was very close to not being.
“Take each day as it comes, they say.”
She said there were no lasting ill-effects, but added: “You are sharply reminded that every day is a bonus really.”
Princess Anne, sister of King Charles and one of the busiest of the “working royals”, has no plans to retire.
“I don’t think there’s a retirement programme on this particular life,” she said.
“It really isn’t written in, no. It isn’t really an option, no, I don’t think so,” the princess said of any plans to cut back on her working life.
