I have trouble understanding jealousy, not necessarily jealousy itself but more the way it affects the perception and actions of others. I've seen people attempt to sabotage the work others. I've seen people gravitate toward friends who have fewer material possessions than them. It doesn't even matter if it's family. If someone has jealousy issues, they might even have negative feelings toward family. I just wonder how small of a person you have to be inside to let jealousy rule your actions and your emotions so thoroughly. Are we really that greedy that we can't bear the thought of someone having something we don't or doing something we can't (or won't)? We are all individuals. We all make unique choices that lead us onto one path or another. Let us not be jerks because someone chose a different path.
To quote someone (I don't remember who) - Don't hate. Congratulate.