Just like every item in the kitchen larder has a shelf life, relationships have a shelf life too. We get the best out of relationships, by being as productive together as you can be, when all parameters are favourable. Distil the best lessons learnt, and incorporate those into your wisdom and intelligence.
How many times do you wonder why people speak and act differently? There are multifarious aspects to a personality, and we connected with a few. The other sides emerge as we moved along. If the new 'them' does not suit our style, let them go.