How much stronger is marijuana today than years ago?

YES. In an article by Rosemary Black in the NY Daily News, May 15th 2009 it was reported that in 1983 the average percentage of THC was less than 4% and now the average is just over 10%. So, imagine if it took you an hour to drink less than 4 beers usually, now think of drinking over 10 beers in the same period of time.