When we idealize someone or put them up on a pedestal, we can be easily disappointed or hurt by them. We see them as above reproach, and almost super-human~ which sets us up for thinking they'll never let us down.
Feeling disappointment is inevitable, if you're human. Nobody is beyond dishing it out or receiving it, but our belief that it's not supposed to happen in either case, is what can set us up for a huge fall.
For one thing, we hold others to impossible standards of behavior, if our expectation is that they'll never disappoint us, and for another, we hold ourselves to them! This can have us walking on eggshells and being hyper-cautious when it comes to our interactions with others, and that's not healthy.
I wrote recently about a friend who'd hurt my feelings. Over the decades we'd been close, I'd come to expect it~ but that didn't make me immune to getting my feelings trampled on, the last time it happened.
My issue with this long-time friend wasn't that he'd once again hurt me. My issue, was that he had zero interest in mending the rupture. When your narcissism is such that you carry too much shame around having made a mistake, you can't own it~ and worst of all, you can't heal the breakage between you and someone else, so the fabric of the friendship frays and becomes very thin, and it can't be restored to whole and healthy again.
It takes the willingness of TWO people to mend a relationship rupture. It cannot happen, with just one. Both parties have made contributions to upsets in a relationship~ even if only one refuses to communicate their honest feelings about something that occurred to undermine the trust between you.
Fully formed, well-developed adults are willing to talk thru their upsetting incidents, hard as it may be, and reach resolution and healing, but it takes two. People with narcissistic or borderline traits have a hard time with confrontation of any type, and their inclination is to routinely sweep a lot of subtle feelings under the rug.
What this means is, no upset has a chance to get resolved. The hurts just keep piling up, the rug gets lumpier, and one day, feelings become so overwhelming, it makes one want to 'cut and run,' rather than working to resolve the conflict.
Idealizing someone is dangerous, because when (not if) they disappoint you, there's no where to go from there. They've fallen from grace with you, and closing that door on the relationship or friendship seems less painful than working to keep it open for as long as it takes to restore trust in one another.
Couples typically have dozens, maybe hundreds of little emotional divorces during the course of their dance together. This happens, because one or both parties are too afraid to speak their truth, and air their grievances.
Relationships are like volcanos. If they don't let out a little steam now and then, they tend to erupt with destructive force~ which is why our divorce rate is sky high.
Think about this for yourself. Do YOU have enough emotional development to risk verbally working thru a relationship rupture with someone~ or are you prone to betraying your real feelings by keeping quiet, and continuing to sweep 'em under the rug?
Even the BEST relationships can trigger feelings in us that are a bit uncomfortable or even, dangerous at times. These are opportunities for growth and healing~ so, if you're still running away from these events rather than walking toward them to try and fix what got broken, that's likely gonna be the source of a lot of failed attempts at bonding with another~ no matter HOW perfect you perceive someone to be for you, at the start.