Mercury enters Cancer on June 16th, where it will trine Neptune in Pisces. Cancer is subjective and childlike, swamping Mercury's objectivity. Add the connection to Neptune and you have idealized (Neptune) thoughts (Mercury) of the past (Cancer).
This is also an empathetic, creative aspect. Neptune breaks down barriers, opening Mercury in Cancer to almost anything (once self-protective fears are put aside).
If you need to reach out to someone or get past a creative block, do it right away (June 16th or 17th). Mercury will be moving towards an opposition with Pluto in Capricorn which will be exact on June 19th. This will cause hesitation and frustration as powerful, outside authorities (Pluto in Capricorn) clamp down. The Capricorn/Cancer opposition involves parent/child interaction. Mercury will want to communicate but will run up against power plays and judgement.