Re: #2 - you are also far more malleabele in your 20s.
Perfect matches are perfect because people change, yield and adjust to each other's quirks. The older you are the less flex there is. It's really quite simple.
This also related to #1 - a prerequisite for making a good match is the willigness to change. However a large pool of choices entices one to search a bit more for a match that requires less change, making it hard/er to try and commit to what might be already in place.
Perfect matches are perfect because people change, yield and adjust to each other's quirks. The older you are the less flex there is. It's really quite simple.
This also related to #1 - a prerequisite for making a good match is the willigness to change. However a large pool of choices entices one to search a bit more for a match that requires less change, making it hard/er to try and commit to what might be already in place.