This refers to a bad habit of many amateur players of falling into the trap of trying to capture a couple of enemy stones in elaborate way while failing to take the overall board situation into account.
Tesuji intoxication often leads to either:
A) Capturing 2-3 stones in gote while allowing your opponent to play a major point on the board.
B) Allowing your opponent to build up a powerful wall in exchange for the stones so that your loss is often guaranteed well before the endgame.
C) Playing a tesuji upon seeing it, which often is Aji keshi.
Tesuji Intoxication seems to be particularly rampant in handicap games.
Somehow I feel this happened to me when I was 20-10 kyu. After reading the book "Tesuji" I was confident that these tesujis will happen in almost every position and playing them is a good thing. Even though I was wrong, I think it was an important, long lesson on the way to get stronger. Tesuji Intoxication can only be cured by time. Vesa