Xcode pedido Optional ao setor o textLabel

Na parte que seto o texto no textLabel o Xcode reclamou e só funcionou quando coloquei o optional, por que?

cell.textLabel?.text = meal

No video o Guilherme não precisou usar.

Segue o código da minha viewcontroller

class ViewController: UITableViewController {

    let meals = [ "eggplant brownie", "zucchini muffin"]

    override func viewDidLoad() {
        super.viewDidLoad()
        println("view did load")
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return meals.count
    }

    override func tableView(tableView: UITableView,
        cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
            let row = indexPath.row
            let meal = meals[ row ]
            var cell = UITableViewCell(style: UITableViewCellStyle.Default,
                reuseIdentifier: nil)
            cell.textLabel?.text = meal
            return cell
    }
}