For one character to meet another character, they generally only have to be in the same place at the same time. If you (fred the first level) desire to meet someone, then you should find out where they are, and go there.
Discounting the curious circumstances needed for one to fall at the cliff, it all depends on whether "Fred" and the wizard in question are the same person. Assuming that they are, the most important detail is whether the two exchange names and pleasantries after the rescue.
Possibly Erathaol the Seer might see that saving the life of one person is critical to the future. Possibly the low level hero has a destiny, or is the descendant of a legendary hero.
One possibility for a campaign might be to gather a party where various powerful figures have intervened in the lives of the PCs for some greater purpose. Of course, there may be other powerful figures backing up the PC's foes.