I have often encountered people who say they are not jealous of their friend's success or feel anything of that sort but believe me they are lying their teeth out.
When someone we know sets up a startup and it becomes successful or gets a high paying job or has a good looking girlfriend/boyfriend or accomplishes anything for that matter, we like all other descendants of homo sapiens start feeling jealous of them. But when similar things happen to any of our close friends we tell them that we are happy for them and have always believed in their abilities, but, deep down we start getting these feelings somewhat related to jealousy and self-pity and we start judging ourselves with all the looping thoughts and self-criticism and consequently burden ourselves with all the guilt which a relationship can bring along. Most of the times to satiate our consciousness we start giving these excuses to ourselves that these feelings are embedded in our systems because we believe that positive competition is the pre-requisite for a healthy society hence we are not jealous.
So instead of feeling blue all the time whenever we encounter such situations ourselves where we have to constantly feed our consciousness with all sorts of excuses, we should cut some slack and face our guilt with accepting the fact that it is alright to have feelings like these, this is normal and believe you me this happens with almost every person who is ambitious enough to have high goals and want to reach somewhere in their life and it is not jealousy or any negative feeling, it's just that someone's time has come and your time is around the corner and that is going to happen very soon.
With this thought process, you will understand that the feelings you were having were neither of jealousy nor of healthy competition and you will make your way through this.
Many of you must have agreed with me here and may have empathised with the above thoughts as it must have happened with most of you also but I would like to tell you just one last thing, Truth is that you are actually fucking jealous of your friend and you are a horrible person who can't stand your friend's success!!