I believe the difference between these two have been questioned many times in many minds.Maybe it's just basically the way we all comprehend.If you think about it then think about a child.If you were to explain something confusing to them then their minds would only comprehend what it has the ability to understand...which in turn may miss the most important points of that subject..Therefor knowledge and living come forth.
Now my opinion on 'true love'...well when I hear someone say the have found their 'true love' I picture someone who has found someone who will love them like no other ever has..which is great...but this doesn't mean they both share in that ability without either having to say a word..no need to explain what it is you truly need.
To say you have found your 'soulmate'...now thats a different story..this to me is two people who share a heart..the give and take are evenly given.A total completion..it's that one thing that is so worth the wait...the thing we all search for..the thing that no amount of money could buy..