Every decission we make in life, marriage, children, school, career, etc. requires change and compromise. Even when the pluses outway the minuses, we still find that we miss or long for the things we willingly chose to give up or compromise on.
When we get married we give up a lot of the control we once had, we loose privacy, the laundry has doubled and we have to use a bathroom after someone forgot to put the seat back down. I challange anyone to tell me they have never spent some time wondering/wishing they were single again, no matter how much they may love their spouse. Of course, eventually we realize that the sacrafice is worth all the compromises and we find some way to re-gain a balance.