"Naturally, whenever you play a test at big grounds different pressures can affect you,"he says. "You need to keep making small steps to put those peripheral things to the side. When you're relaxed and clear, a routine can happen instinctively. You're able to let your game go."
If any New Zealander is to join the 16 on the visitors' honours board, Williamson must be at short odds. His three other test centuries each came in high-pressure circumstances. He made his first on debut against India in 2010, his second came to save a test against South Africa in 2012 and his third was part of a 262-run third wicket stand with Ross Taylor in Sri Lanka to help resurrect New Zealand's test reputation after five straight losses.
Williamson has put in meticulous preparation behind the scenes - right down to the reaction of his sinuses - to give his instinct room to roam. He spent 10 days with Gloucestershire, under former New Zealand coach John Bracewell, in the build-up. Williamson has played for the county over the past two seasons.
"I even got used to batting with a runny nose in the cold. I have a good relationship with John. It worked from a skill perspective and he's someone to bounce ideas off and spend time with."
Other than a Lord's tour with the New Zealand under-19s and a brief appearance in one of Gloucestershire's pro-40 one-day games, Williamson's relationship with the ground is limited. He says he didn't even walk out to bat through the Long Room. However, the memories are etched, particularly at lunchtime.
"The meals are outstanding. I think I had a stir fry. You take a seat, order from the little menu on the wall, and wait to be served. They do it so well. Everything that happens is done to a 'T', right down to the polished cutlery.
"You always want to play at Lord's but you start to understand the importance of playing here as you grow up."
