Do I really need to flex? 😩

Hey IH!

It's been a while since I posted anything. Since my last update, many things have happened to my project and me. I quit my job and started working full-time on Coolboard. I built an amazing team: a guy from Google agreed to join me as a CTO, we have an ML engineer, a web-developer, a QA, and a graphics designer. An angel offered investment, but I asked him to wait. Our product is now approaching public beta. And we're in the middle of rebranding everything: we will rename Coolboard to Riddey. Our new website will be up soon.

But the reason I write is that not long ago I had a meeting with a guy, an ex-manager of mine. He also started working on his project after quitting.
And the way he talked about his stuff was so. How should I say? Intimidating? It made me feel like I am a loser. It is probably not his fault, but my inferiority complex. Or maybe it is because of him: we had a 45-minute meeting, and while he spoke roughly 40 minutes, I used only 5. But he seemed so confident, and someone who is 100% sure about his product. He also told me that he did not need to pitch his idea investors just started throwing money at him. And set up a pilot at even large companies, etc.

I just wanted to ask your opinion. Is it necessary to brag when you talk about your project/company? Is this normal in the US? I am from Eastern-Europe and there it can easily backfire if you do it too much. I guess I should change and start showing off. What do you think?