When I was growing up, I always thought relationships had to be 50/50. Give and take needed to be equal or the relationship would not succeed.
In reality, what I discovered was that relationships almost always consist of an unequal number of contributions. If one person is having a great day, they might contribute 80%. If the other person was having a bad day or a troublesome day, their contribution might only be 20% or less. The goal was to have the total equal to 100%. Unfortunately, that didn’t always happen.