This reminds me of the saying:
If you love something, set it free. If it comes back, it's yours. If it does not come back, it was never meant to be.
Building bridges is extending the olive branch, breaking the ice to get the communication started again, and to make a new connection!! Sometimes the effort is all one-sided, and you know the effort is probably fruitless, but you make the effort regardless...because you are the bigger person. It may seem to go unnoticed by the other party, but not always. It may be closing the gap slowly, it takes time for both sides to reach each other. Time might be the only healing power to bridge the gap. Change also brings the chance to close the gap, when one person finally has an "ah-ha" moment, and understanding and wisdom floods their consciousness.
This is the point when bridging the gap has turned into opportunity to really repair the relationship, and continue healing each other. If you can make it this far, you will get the warm and fuzzy feelings again! The relationship will never be the same, of what is used to be - so don't expect this!! You need to acknowledge that was the past, and pull out the memories good and bad to move forward. Keep moving forward might take more effort than you are willing to give! However, if this relationship means anything to you, you will look for ways to keep building the bridge.
Just realize when there isn't any hope left, you don't want to try to keep riding the dead horse, at this point, it's time to give up. You never know, you can try again in the future when there is a flicker of hope.
The main point here is to be open to the possibility to build a bridge with your lost connection, if it feels like the right thing to do. The effort could bring you both closer in an enriched connection, making the time lost as a growing period of wisdom and maturity to get to the next level of the relationship!!
:)