I read a good quote that seems particularly appropriate for travelling and friendships...

"We have so little faith in the ebb and flow of life, of love, of relationships. We leap at the flow of the tide and resist in terror its ebb. We insist on permanency, on duration, on continuity; when the only continuity possible, in life as in love, is in growth, in fluidity...Security in a relationship lies neither in looking back to what it was in nostalgia, nor forward to what it might be in dread or anticipation, but living in the present relationship and accepting it as it is now. For relationships, too, must be like islands. One must accept them for what they are here and now, within our limits - islands, surrounded and interrupted by the sea, continually visited and abandoned by the tides".

Anne Morrow Lindbergh