So when you were born he was already out in the bars drinking and carrying on for two years as an adult.
While you were in kindergarten he was tearing it up with what his first? second, 12th lover? (you: 5, him: 28)
He grew up in a totally different world than you did. His thoughts and habits were formed by a world WITHOUT MTV, without cable TV, (hell not even HDTV). We didn't have computers in every home, no internet, no instant messaging. We had to go home to use a landlines (and many of us had a rotary dial that took like forever to dial a phone number). When we left home we were totally out of contact for HOURS. And it was so for all of our friends as well.
Can you comprehend that world? Can you envision how we lived and how we developed socially in that world where everyone was out of contact?
Tell me, did you watch Andy Koffman on the show
Taxi - Lots of kids did, it was a big deal. Let me list a few more names that were well known by my generation when we were kids:
Bob Marley, Carroll O'Connor, Divine, Walter Cronkite, Steve Clark, River Phoenix, Johnny Carson... Hint: They are all dead, most were on TV back when I was growing up.
I was with a couple of guys who were 15 years my senior, and just 15 years was enough to cause us to be two different. Yeah sure I knew about the Civil Rights movement and the protests and Woodstock. I was 3 years old when Woodstock took place, One of the guys I dated was 17 and was there.
By the time I was 17 the world was a much, much different place. I actually cannot 'relate' to the world of the 1960's - I was alive, a baby, a toddler - in elementary school thus all of those things of that decade were pretty alien to me.
You are going to have the same problem. The 1980's and the 1990's YOU Are going to see through a child's eye. He will be looking at these decades as a young adult.
Those decades formed him, formed his opinions (and mine too and anyone else 40+) We are products of those times and no matter how cool we are with our touch pad phones and being on the internet, we are still products of the age before these technologies.
Sure, he can be your friend, and he most likely has some worthwhile advice to throw your way (which you being 20 will discard and see as stupid, until you are 40+).
But can you really be lovers? Mates? Companions who can relate to one another on so many levels that are tied into to the times and eras and cultures that we are raised in?
I'm not saying it won't be fun - but there will be a missed connection between you two. He will look back fondly at the era of Reaganomics and you will be saying 'Ray-gun what?'