People enter your life for three purposes.
The key is to know which they entered it for.
The reason. A guardian angel, usually to meet a need you felt or expressed, through hard times or good times, they offer support and guidance, they assist you, you may assist them. To help you grow develop and learn, or for you to help them grow, develop and learn, then, for either no reason or there may be a reason, they disappear from you’re life, needs have been met, the work is completed, just find the lesson in it. Sometimes you may need to look harder than others, but there is always a lesson to learn from these people.
Season, A short time, people may appear for a short time, be it months or years, it may be for you both to experience joy and laughter together or face a difficult situation, together. They can give you, and you them great joy, believe it and feel it, what you felt was real, they may give you great sadness again, believe in it and feel it, how you felt was real, good or bad, find the lesson learn and grow from it. One of you may need to move away, one may say something to end it, sometimes they might act up and force you to take a stand and walk away, or for no wrongdoing on your part they might be the one to walk away. whatever the season they were not meant to stay.
Lifetime, A long term permanent connection.
Things two people build on, through the good and bad, connecting together, supporting each other, build and grow together, to teach each other a lifetime of lessons, build upon solid emotional foundations, to love each other, learn from each other, pick each other up.
If they appear for a reason, season or a lifetime, it’s to aid physical, emotional or spiritual growth, there is always a lesson for you to learn, you just have to find it learn from it and accept that they were in your life for one of the above three purposes.