If you find that you just can’t live without Photoshop’s standard shortcut set, getting it back is easy.
Open the Keyboard Shortcuts dialog box by choosing Edit>Keyboard Shortcuts, select Photoshop Defaults from the Set drop-down list, and then click OK.
Of course, if you need them, any custom shortcut sets that you create are still available. You can select a custom set from the Set drop-down list in the Keyboard Shortcuts dialog box at any time.