I think it's just easier for some people than others. For example, easy for me, hard for my DH. I think that's just because I don't really get too attached to much, and for DH things bring back memories for him so he does get sentimental and doesn't want to part with something. He still has the movie ticket stub from our 1st date, and the napkin I wrote my phone # on the night we met. He also has all the letters he got from his friends when he was away at college. I honestly think that if a tornado came and took everything away, I'd be ok so long as no one was hurt. I would only be upset about losing the photographs because they can't be replaced.
My mother has a hard time parting with things because she's afraid she might one day need it. Maybe because she grew up really poor. But she even saves things I can't for the life of me understand. She actually has every single bank statement neatly filed since 1969! I told her she doesn't need to save them, but it falls on deaf ears- oh well, if it makes her happy.
I hear the general rule of organizers is, if you haven't used it in a year, get rid of it. That's the rule I live by. DH?....he just says a house should look "lived in"- lol. Some of my kids are like me, one is like him (squared).
So, when they aren't home, I occasionally get rid of things that they can't bring themselves to get rid of, but never use, and have forgotten they even have- nothing truly important. My son would still have his baby toys, if it were left up to him- and he's almost TWELVE. I think he just can't SEE it go, but is fine so long as he doesn't witness it leaving the house.
I hear you about the toys. I have 4 kids, and sometimes I feel like the Grinch when he says "The toys, toys, TOYS!" in his grinchy way. I talk to them all the time about children who are poor, and don't have many toys. 2 of my boys eagerly go through their stuff, and throw toys they don't use into bags for donation. My oldest son... I can see he wants to, but he just can't do it- can't let things go- because he remembers all the fun times he had playing with EVERYTHING.
The problem most of us have is feeling overwhelmed at the monumentous task of decluttering the house. Where do you even begin? I once read in an organizing book to break it down into psychologically managable small tasks.
Plan, for example, that on Thursday you're going to tackle the hall closet that day. Don't just set things aside. All the coats that no longer fit- put them in a bag, and then put the bag in your car so it can go to Goodwill. Things that don't belong in there- put them wherever they belong. Take everything out. Ask yourself, "do I need this?" and "does it belong in the coat closet?" For example, maybe you've always kept the board games in there, but could go on a shelf in the family room or in a child's bedroom.
Anyway, once you've tackled the closet, you'll feel so good about the way it looks, you'll be inspired to organize other areas. If you know you'll have an hour or 2 one day, tackle a junk drawer or under the bathroom sink. Before long, the whole house will be done.
Good luck!! =o)