Why is it so hard to let go?

Recently I’ve been noticing a common theme in my own life of being in a variety of seemingly different situations where the underlying common thread is ‘letting go’.  The first is one where my family is having some work done on the second floor of our house this summer that requires me to pack up all of our personal belongings up and store them.  My goal is to only pack things we actually use, keep a few sentimental items, and donate the rest.   Sounds like an easy plan but it’s been so challenging to decide what to keep and what to ‘toss’ that I am finding myself avoiding the whole thing altogether!
A second ‘letting go’ scenario for me is my son will be starting middle school next year and is now becoming much more independent (which I know is what’s supposed to happen!) but that too is hard to be at ease with.   I miss my little boy.
In the meantime, I purchased some new everyday dishes that I absolutely love.  My previous dishes were over a decade old, had many chips in them and it feels so good to not use them anymore!  The problem is, I am so attached to keeping these new dishes in perfect condition that I practically hold my breath when anyone touches them.   I am so fixated on being slow and careful when I load them in and out of the dishwasher.   Well, guess what happened!   One day after preparing a delicious lunch for myself, seemingly out of no where, I literally dropped my new dish and it broke into so many pieces (and lost my yummy lunch too)!
Life continually brings situations to us, in order to teach us what we need to know. (Clearly I have missed the point more than once on this current lesson!).   The bottom line is, many of us need to be more comfortable with letting things go.  Sometimes it’s a long held grudge.   Sometimes it’s a friendship that we have outgrown, sometimes it’s new dishes!  No one has control over anything and once we can truly realize this, we can roll with life’s changes with ease and grace.  What do you have a hard time letting go of?  I’d love to hear from you!