"Nobody who plays good chess plays this line, and nobody who plays good chess ever will." says Sam Collins in his Understanding the Chess Openings introduction to the Blackmar-Diemer Gambit.
Which is also a lead-in to my opening philosophy. My philosophy is best summed up in the classic joke:
Two guys are in the jungle when they see a lion running towards them. Frantically, one of the men starts putting on his running shoes.
Surprised, the other man says " What are you thinking, you can't outrun a lion!!!"
" I don't have to outrun the lion," said the man, " I just have to outrun you."
You do not need to know your opening lines 17 moves deep. You only need to know your opening better than your opponent. This is one of the reasons that my repertoire contains uncommon lines and gambits. It keeps my opening study to a minimum. The game becomes a chess contest instead of a memory contest.
Today’s game is another BDG in which my opponent departs from book early, and then the fun begins.
Lesson learned: When playing gambits, it is important to keep the initiative.