It's not fun being someone else's emotional garbage can. They dump stuff on you so they can be rid of it themselves.

That having been said, I reckon the 'soulmate' meme is fairly damaging to both participants, although it does allow someone to project all the virtues in the bible onto a partner who probably can't sustain that level of expectation, particularly if young. But that is just my opinion. Gordon Lightfoot's song If You Could Read My Mind being a fairly harsh illustration of how it feels to be the recipient of unrealistic expectations.