Smith has played 110 test matches for the Proteas and holds the world record for the most five-day matches as captain, 102, but he admitted to nerves before the team departed on Friday.
"It feels surreal to be sitting here today," he told reporters. "When I went into surgery five and half months ago I knew it was going to be a long road back.
"And it was, it three months on crutches was hard and it hasn't always gone smoothly. Right now I feel like I am going on my first tour in a way, just with lots of experience.
"I am nervous, I have not played cricket for a long time and I will need to maximize preparation with just one warm-up match before the first test.
"I need to make the most of the next 10 days. I need the experience of being out in the middle again in order to contribute to the side like I want to."
Doctors are hopeful they have finally solved Smith's chronic ankle problem, helped by custom-fitted boots that should more evenly distribute the weight on the joint.
He admits periods of the last few months have been disheartening and painful, but remains motivated to play more matches for South Africa.
"I still have the drive to want to play at international level, I still feel like I have the motivation to do it. When you have been captain from the age of 22 and helped to develop a team, you want to see it through.
"There were days when I was really sore, but I had a lot of phone calls from team mates and (coach) Russell (Domingo) checking up on me and that really made a different to know that people still cared."
Pakistan beat England 3-0 in their last series in the Middle East in January last year.
"I watched the series, the ball spun a bit but I thought England weren't as mentally prepared as they could have been," Smith said.
"We understand the style of cricket we want to play, we understand how to be successful in different conditions.
"We expect the wickets to spin, we expect the worst in that regard, and (Saeed) Ajmal and how we handle him could be the key to the tour."
South Africa beat Pakistan 3-0 in their home summer last season and have only lost three of their previous 21 five-day matches against the sub-continent side.
The first test starts in Abu Dhabi on October 14, with the second set for October 23 in Dubai. There will also be five one-day internationals and two Twenty20 matches.