How do I stop thinking of past failures with old acquaintance I bumped into?

It's known that comparing with other peoples life is the reason why we get to feel unhappy with our life.

The most annoying thing is to hear from other to think of happy thoughts and what it's nice in your life, but the issue here is that you won;t be able to do that (because, in the moment, you are fixated on the negative thought and you can't find a good one)

I recommend you to think from another perspective (the perspective is everything, like the half empty/full glass)

Think it this why:

In order for him to to have gotten where he is, he mast have sacrificed something in his like. (we only have time and energy to do some things, but not all)

I don't know him, and i don't know exactly what example to give you to spark the right feeling, so please take the example I'll give and think what is what he sacrificed and you did not. Ok?

In order to succeed in something, is a mix from passive behavior and Active/willing behavior. The active behavior takes the most of our energy& time. through this he might have lost friends (no time to connect with the properly), precious moments that you don't know about; He probably had to sacrifice personal principles to accomplish some goals (if that happen is is most certainly hunted because of that when he's trying to sleep)

What I'm trying to say that things did not come that easily for him either and that he suffers somehow too from what he had to do.

Now back to you. We all have things in life we take for granted. In my case were my parents. I had to almost lose them, in order to know what i have everything. For me, family is everything, but i never though about my first family (the parents), but somehow only about my future family (wife, kids etc). We always have things we take for grated, just we don't realize it yet. (this is what people mean with "think about happy thoughts" )

I, myself, I'm confronting with something similar now, and what I'm writing to you is also a reminder for me as well.

I think that we all have everything and nothing at the same time.

(this is how my childhood was as well. I had everything i needed, modest food, modest house, but nothing more. "Everything and nothing")

Now, to answer to your question..

Find something in your life that it's unusual, something good (not necessarily great), something to provide you with a steady good feeling (let's name it something that keeps you with your feet on the ground)..

Second, find small goals to boost your energy. (in my case was once that i wanted to make my house a smart house (with as little money as I could), just because I wanted to hear music before i even was awake to hear. stupid... i know, but it was something that boosted my energy after I finally managed to do that.)

Third thing, when you feel good with yourself (from the boost) and when you feel steady there (happy), you need to prevent that from happening. Speak with your friends, family, strangers (homeless if you have the chance >>joking<<) and try to understand what you can to to prevent that. Find what makes you happy... If you can self analyze yourself deep , correct something from your personality, so that you will do things passively (good) without needing to think (actively)

I repeat... I don't know you and I don't know him (how he triggers your pain), but I wish if you could take what I told you so far, to apply it as closely to your situation as you can.

I wish you all the best! Speak about this with everybody you can, even when they ask you "how are you today". Don't just answer "I'm good. you?".

we all suffer in some way, and you never know who could be your solution<<<