Don't let comparisons steal your joy. -Unknown
The only comparison that one should consider is her past self to who she is now to who she wants to be in the future. All other comparisons should be banished away as they may serve to erode away at your self-esteem unless we use them as motivation to get us to the next level. Beyond using it as a motivation tool, comparing yourself to other people in terms of what they appear to have or not have is like practicing magic. The life that other people appear to have is an illusion of the image they want to send out. It is not a realistic view of their lives. It is not a real view of the pain, hurt, or complete feeling of loss they may be experiencing. An outwards appearance, does not take into consideration the genuine ups and downs that everyone goes through.
Do not let anything steal your joy. Joy is precious and comes in spurts. When you have some joy in your life, hold on to it, nurture it, spread it, live in it, and enjoy it. Life is not without it's ups and downs and there will come a time when you will feel as though joy has been snuffed out of you. Be mindful that it is not. It is just making room for you to work through your emotions so that it will be loud again. Life has enough issues to keep up busy. That is why it is especially important that we do not manufacture reasons to lose our joy.