I guess its a matter of perspective. I mean, if girls did that there would be divorces left, right and center.
But if a guy keeps his past memories with him, we hear "Get over it, you're not allowed to be mad at us for this!" or "we're too lazy to make you happy, its yahoo's fault for giving us all that space!".
In a relationship, you're only going to get what you give. So, if this is the example you want to set...by all means go right ahead. However, you lose the right to complain when you find cards and such in your wife/fiance's possession that were gifts from an ex.
Oh no i really don't think about it that much, i have given enough confidence to my wife that she shares almost every thing with me, if i found something about her accidentally then again i shouldn't be bothered about it, like may be she have a very good reason for not to tell me and let her select the right time to let me know about it if she wants me to know.
Quran says that, one should not draw conclusions about others as it may make you a sinner, todays world we muslims consider quran a bore book with few stories of ancient times in it, tends to learn nothing from the book and keep on saying that WE ARE RIGHT, WHAT EVER WE DO, HOW SILLY IT MAY SOUND, STILL WE ARE RIGHT.