I am having trouble with these verbs. I know in the pass tense with a trip that is already completed (you have returned), you use ездить (because it is multidirectional). What I do not understand is if you have completed a trip and only went there once, why you still use this verb (as far as I understand it, you do). Wouldn't you need a perfective verb to imply that you only went there once? Does this not imply multiple trips? When is поехать used?