As the time when we can throw our windows open and embrace fresh air nears, so does the overwhelming urge to get rid of the clutter we've amassed in our homes all these years.

Each year, the beginning of spring and nicer weather marks a time for people to clean out their houses, revamp their style and hold garage sales to get rid of all the extra junk they've been keeping. Except, of course, for that extra junk we can't bear to part with.

"The amount of stuff you have is a function of time and the space you have," says professional organizer Clare Kumar, who, thanks to her job, has learned quite a bit about the psychology of discarding loved items. "If you have tons of space, you aren't under pressure now. But you want to think ahead and prepare for a time when you want to downsize, and have a strategy to do so."

The things that people keep vary immensely by personality — "I've seen lint brushes in every drawer, or 30 sets of sheets," notes Kumar — but there are definite commonalities, and most of them relate to emotions. She lists five reasons why people can't let go: sentimental value, potential value, current value, guilt value and identity value.

It's easy to picture what each would entail (admit it, you can envision one for each category in your house right now), but Kumar does have some suggestions as to how to make parting with these items a bit more painless.

Check out this list of the 13 hardest things to throw away — and why you should it anyway:

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  • Wedding Dresses

    Clothing is a massive category when it comes to hanging on to things, but wedding dresses in particular (given their hopefully one-time use!) take up a lot of room without giving back. They are, however, the height of tangible sentimentality. If you weren't savvy enough to sell it within two years after the wedding, notes organizer Clare Kumar, it's probably out of style. Here's hoping a family member will want it!

  • 'Skinny' Clothes

    It's relatively simple to get rid of the clothes that are out of style, stained or ripped, but what about those items you still love — but don't fit into anymore? We've all had the "skinny jeans" dream, but perhaps it's more worthwhile to reward that kind of weight loss with a new, fresh wardrobe instead.

  • Kids' Clothes

    Besides parents who hold on to clothes in case they have another child (which is just smart, financially-minded planning), keeping kids' clothes in case they want them when they grow up creates a potential hoarding spiral. Instead, Kumar encourages people to use your camera to its advantage, and take pictures of the cute outfits when the kids are wearing them, and relinquish them once they're too small.

  • Children's Art

    As much as you may want to preserve your children's artistic genius for years to come, either for yourself or for them, those drawings and macaroni necklaces can add up. Kumar suggests, first of all, curating the really good or special items, and secondly, <a href="http://www.artkiveapp.com/" target="_blank">looking into apps like Artkive that can digitally store all the work</a>.

  • Gifts You Hate

    It's so amazing when people give you presents — but so difficult when they're hideous, or useless, or generally something you didn't want. So what do you do with a gift a friend or relative is expecting to see in your house? Get rid of it, says Kumar, and feel no guilt. As for what to tell them, well, "things get broken!" she says.

  • Stuff That Was Expensive

    If, once upon a time, you put out a lot of money for an item, you often feel guilty getting rid of it, even when it's out of style or no longer something you love. "You have to give yourself permission to let it go," says Kumar. If you really want to try to get the money out of it, look for someone to value it, or find a consignment shop. But don't forget, that's a time investment as well.

  • Paper Memories

    Anything from plane tickets to concert tickets to wedding invitations can take up a lot of space (and look pretty messy too). "I think we're worried about losing being reminded of it, so we hang on to all of this stuff so we have a memory trigger," says Kumar. She suggests using the digital camera trick for these items as well — snapping shots and preserving the memory digitally so that worn pieces of paper can go in the garbage where they belong.

  • Magazines

    Magazines are paper, but they're very specific paper — whether you're a junkie who loves looking through old Vogues, a National Geographic addict or a House & Home resource centre, keeping stacks of magazines can create build-up quickly. With this one, it's a matter of taking a deep breath, heading to the recycling bin and remembering that most articles can be found online. Except for commemorative issues. Because who can throw those out?

  • Books

    Book lovers know this dilemma well — stacks and shelves of tomes that you just can't picture parting with. "I think we revere books, and rightly so, but they take up a lot of space," says Kumar. "I would suggest it's also a matter of identity. Sometimes we keep things because they remind us of who we are." So if you don't want to quite get rid of your identity, try to pare down — for the sake of eventual moving boxes at the very least.

  • Stuffed Animals

    Childhood items come up again and again in these lists, and that's because of the memories attached — and in many cases, the memories we hope our own children might make with our things. For Kumar, plush dolls were something she couldn't get rid of, until she took a snapshot of her daughter surrounded by five beloved dolls from her own childhood. "Then I was able to let them go," she says.

  • Extra Kitchen Items

    Kumar calls this the "Boy Scout syndrome," the need to be prepared "just in case." This also tends to fall into the "what if my kids need it" category. While it's a nice idea to have extra items around, you need to focus on the life you're living now, says Kumar. "You can get a lot more now through secondhand classifieds than you could before, and if you can be okay with shopping that way, you can trust that you'll find what you need when you need it."

  • Inherited Items

    Particularly in the time soon after one loses a family member, it's hard to let go of what they owned. While you might not want to get rid of things right away, Kumar suggests setting a deadline for when you'll go through it — especially if it impinges on what else you want to do with the space the stuff is taking up.

  • Broken Loved Items

    Perhaps it's a chipped mug that you've had since university, or a chair that wobbles so much it can't be sat upon. Sure, you could get it fixed, "but you have to factor in the time, energy and money that goes into that and sometimes we're not realistic about that part," says Kumar. The truth? That could be the stuff that's easiest to toss.