A guy walks into a post office one day to see a middle-aged, balding man standing at the counter methodically placing "Love" stamps on bright pink envelopes with hearts all over them. He then takes out a perfume bottle and starts spraying scent all over them. His curiosity gets the better of him and he goes up to the balding man and asks him what he's doing.

    "I'm sending out 1,000 Valentine's Day cards signed, 'Guess who?'"

    "But why?" asks the man.

    "I'm a divorce lawyer."

i can't grasp it

the balding man wants to get more business about his job-- the divorce lawyer.

More people get married ,so more people divorce

It's very bad news to recieve a letter of divorce at   Valentine's Day.

methodically有条理的,做事说话有条有理,丝毫不乱
bright pink envelopes 一般指写情书的信封
get the better of 打败胜过,占上风
divorce means the ending of a marriage as declared by a court of law

i should........
mind my own business,sorry