Wow, you are really gonna impress the girls with your knowledge of binary code. I would spring it on them early in the date, start discussing how interesting the binary code is and how you can use it. Doing so will probably save you the cost of a meal, as she will immediatly remember something critical that she must leave to do, or she will remember someone dieing she needs to go see immediatly.
Some of the other great uses for your new hobby:
Putting on a resume under "hobbies" or "interests"
Having it read some sad day when you are eulogized "knew the binary code"
Learning is never a mistake.
dago