How can the journeys of Odysseus be compared to specific real life events?
The journey and wanderings of Odysseus are the journey and wanderings that we all experience in life. Odysseus is seeking to establish his true identity. Like all of us, Odysseus is trying to be who he really is. At one point, in Odyssey 9, Odysseus even sinks so low that he claims to be "Nobody." Only at the end of the epic does Odysseus re-establish himself as the "real" Odysseus. He can, without fear of repercussion or contradiction, say that he is the husband of Penelope, the father of Telemachus, and the ruler of Ithaca.
Like most people, Odysseus also experiences temptation, especially sexual temptation. The goddess Calypso tempts him with life everlasting; the goddess Circe tempts him with a life of pleasure on her island; the beautiful mortal princess Nausicaa presents an opportunity for Odysseus to have a new bride and a new life on Phaeacia. The Sirens tempt Odysseus with pleasure and wisdom:
"No man rows past this isle in his dark ship without hearing the honeysweet sound from our lips. He delights in it and goes his way a wiser man" (A.S. Kline translation).
Finally, like most people, Odysseus struggles to endure and overcome the various obstacles he faces in life. In his encounter with the Cyclops, Odysseus' curiosity almost costs him his life. Odysseus' temper and pride cause him to reveal his true identity to the Cyclops, which results in Odysseus incurring Poseidon's wrath.
In sum, numerous things that Odysseus experiences also happen to us. Of course, we don't literally face one-eyed giants or witches, but we do face the same sorts of challenges and temptations that Odysseus faces. Ultimately, we are all trying to find out who we are and what we are supposed to do with our lives.
I think if you begin to see the monsters that Odysseus encounters as symbolic of more common problems, it becomes easier to relate his struggles to real-life events. For example, when he and his crew stop at the Land of the Lotus-Eaters, several of his men sample the lotus flowers, which have the effect of a drug, and completely lose their desire and drive to return home. We might compare this to drug use today, how people might try a drug, not really thinking through the possible repercussions, and then suddenly find themselves a slave to that substance. It can change their personality and make them forget their values, priorities, and goals. That is what happens to Odysseus's men.
Alternatively, you might consider the sirens. They are the embodiment of temptation and try to entice people away from their paths and purposes. We often use the phrase "siren song" to describe just such a temptation in real life: I meant to study for my test last night, but my favorite movie came on TV; it was the siren song that tempted me away. Similarly, consider this example: I was going to give up sweets for the new year, but my mother's homemade cake was the siren song that broke my resolve.