Like a saying goes, an ex is an example of what you want left in your past! (Ouch) and thats exactly where they belong; in the past.
Ending a relationship is always painful especially where fond and beautiful one-in- a-lifetime memories are shared (trust us some relationships have more sour than sweet memories- thats a topic for another day) thinking about emotions, time, resources and a whole lot more invested into making it work.
So, the relationship could not be salvaged, Oh well! We have got to get it together at one point anyways. But first, start by throwing out everything that reminds you of him/her here are reasons:
The mementoes are basically gift items from the past boo; those birthday gifts, anniversary love gifts, 'Love Forever' bracelets and so on are only reminders of the relationship which only gets you wishing what could have been but unfortunately wasn't meant to be. This is a step backwards; not healthy.
BAD GIFTS ANYWAY
Uhm sorry, but its true! Who needs the 'ugly wedge' he gave your on your 21st birthday or the 'fiorelli replica' bag he bought specially for you to mark your anniversary, they are bad gifts anyway why hold on to them, by all means toss 'em.
As far as you are concerned, they decided they don't need you anymore in their life why should they be in yours? The point exactly. If they don't want you in theirs, they have no right to be in yours.
You need to get out and find your next (hopefully your forever). Once you are past the 'pains' of a break up, get your gorgeous/beautiful/handful/sexy/amazing life back and get ready to get back in a fruitful brand new relationship.
Holding on to what could have being will not only only hurt you it is equally healthy. By all means pick your self up, gather all the strength you need, work, look good and MOVE ON. Make your ex realize what he/she lost and for a minute have no regrets; its just not meant to be!