r/whatisthisbook

Ok, my first time posting in this sub. I am trying to remember the name of a book or the name of the series it was in. I first read this book in the mid 1980s(yes I am d as fuck, hence the failing memory.)

The Main Character was a newly graduated engineering student from poland (or of polish descent) who gets drunk to celebrate his graduation and wakes up in medieval Poland where he uses his advanced technological knowledge to create machines to lift the polish people out of the middle ages and help them become a European power so that Poland will not be invaded so often in the future.

I remember he is gifted lands by a polish nobleman and develops a training program to turn surfs into knights in order to strengthen the polish armies at his disposal.

I also remember that he often makes machines that are more intuitive than their 20th century counterparts like a plane that turns right when you turn the wheel right because the control linkages are easier with the tech and materials available to him but constantly moans to himself about such things which is a line I remember vividly as it is repeated several times throughout the book series, "God , I know we're polish but must we do everything backwards?".

The gist is that he slipped back in time due to an error by a time traveling organization from the future who anonymously gift him a sword with a molecular edge made of diamond making it nearly indestructible and able to cut through almost any thin(depending only on the strength of the weilder) this sword is left for him the the time traveling group because the head of the group is a decendant of the Main Character.

That is as much detail as I can remember at this time.

If anyone can help with the title, the name of the series, or even the author's name, I would be eternally grateful.

I took a course in abnormal psychology back in 1988 or 1989 in college. I didn’t realize it then, but my professor was introducing us into woo, how to look at beliefs and let go, trust the universe etc. There was one required book he made us read that did all the above. It was almost like a life guide book. It had cartoon like drawings throughout the pages. I remember it changed the way I saw things and I am trying desperately to find this book! I remember it was a male author and it had to be written before 1988. Any ideas?