To become extremely fascinated and or nostalgic/longing for past events. "Retro" meaning "the past" and "trip" because you get lost and trip out on things that you still remember. It can also be portrayed as wishful musing about certain events in history. You do not need to be high while under the influence of this highly-natural state of consciousness.
If I could go back to a different era in time, I would like to see what life was like during the roaring-20s. All that free alcohol and underground clubs, not to mention the Harlem Renaissance. The 30's presented to us a golden age of movies, the 40's was notable for popular icons such as Frank Sinatra. The 50's pretty much sucked, except for the beatniks~now THOSE people had it goin' on. The 60's was all about freedom and rebellion, not to mention the birth of the modern horror movie (look up Psycho) The 70's were funky and psychedelic, also the starting place for disco. The 80's, as we all know was slammed with violence in the media (Friday the 13th and many, many others...) but the often overlooked aspects include new wave and other trends (like retro-style coke/pepsi cans and rubik's cube. The 90's are pretty much like they are today, except that hip-hop was just getting started with artists such as Slick Rick and Salt 'n Peppa. Now we are here in the 21st century, where everything is digitalized and progressive. Thank you for listening to me ramble about my retrotrip and remember: Always take time out of your day to remember the past.