Past is one of those multipurpose words. It can be a noun, adjective, adverb, or a preposition.
Unfortunately, past has always had its sights set on functioning as a verb. Sometimes it tries to sneak its way in there, but that role is reserved for the word passed, which is the past participle of the verb to pass. This word can only ever be a verb, so it starts to feel antsy sometimes as well.
Watch out for its attempts to be something it's not.