not hard....strip it down to the basics...3 key items that are very simple to understand...
1.can you sit and have a decent meal without an argument with that person?
2.can you enjoy the same type of entertainment?
3.can you see yourself fucking this person from now till death...or at least till your naughty parts stop working?
what are the 3 things that most couples do...eat some food...entertain themselves...fuck...repeat
this isn't rocket science,its not hard,if you don't have those 3 things,move on,things will not click later on...you never see a crackhead that is happily married to a lawyer.
and i know i know..trust..honestly..faithfulness..yeah you can go all Dr Phil about it..but without the 3 key things...the other stuff will never happen
ps...the man that keyed the term "opposites attract" obviously wasn't getting steady pussy