There are so many variables when it comes to a strong marriage or relationship, as well as staying attracted to eachother...just like all of us individually has to work through things in life that make us stronger (deaths, financial crap, arguments that we learn from, etc.) couples undergo the same life experiences together, and the more you stick it out and not run for the hills like BB was saying the stronger your relationship will get and the more you both will continue to fall in love with eachother, at least this has been working for my wife and I...especially when you raise children, talk about stress, teamwork, and dealing with crap lol, I guess my wife and I can actually thank my 19 year old daughter for bringing us as close as we are to eachother because we went through HELL and still are with her, but I seem to fall more and more in love with my wife daily due to what we have gone through together...but we are not of the norm I guess...and we would blow the science theory into pieces, especially the way our sex was last night...it has been 10 years we have been together and all I can say about last night is WOW and I want fucking more of it!!!