I have an idea that might help you and your wife see eye to eye on this. Buy a chest. Spend on it, make it a really nice once, and negotiate on the size. This is now your Memory Chest. The things you want to remember go into this chest. Things from your wedding, your vacations, baby books and booties should you have children, etc. All your sentimental keepsakes go into the Memory Chest.
There's several big benefits to this. The first is that you know where all your keepsakes are and they are stored safely and protected from spoilage. This is a huge benefit to you, you know that nothing is going to get lost or broken or accidentally given away.
To your wife's benefit, there is a limit. You can't keep everything, because your keepsakes go in the chest and anything that doesn't fit is up for negotiation. If you want to put the dress in there, you can, but that means that other large items won't be able to go in. And that's ok! That is still a space for remembrances and what is important is what you two want to remember.
This also becomes a keepsake down the generations. My great-grandmother had a chest like this. I and my cousins had an amazing couple of afternoons slowly exploring the things that she kept in that chest and discussing what they must have meant.
It's OK to keep sentimental things, it is just also important to not let every thing become sentimental and hold on to everything. I think this is a good method of setting a sane limit that lets both your and your wife have a say.
