Well, you said you did have a lucid dream, it's just that you woke up after the realisation, which is the most common thing to happen in your first lucid dream. And actually, it wasn't even your first, for what you said I understand you had had a lucid as a child. This had also happened to me, and I remember clearly the day I went running to my parents saying I had realised I was dreaming in the dream. I didn't know this was such a thing until a year and something ago.

I think if there's one reason why children can have a lucid dream more easily is because they are very curious. They watch everything around them, discovering the world every day. That also makes them more observant in their dreams and that's why they can more easily notice weird things. This is, sadly, a skill we lose as adults, specially with all the stress we live with. When we walk around in auto-pilot mode, we decrease our chances of becoming lucid. It's hard to get out of it and be aware of what's around you, lucid living like a child. I myself struggle a lot with this and I very much believe this is what's slowing down my progress.

It's hard to get started, when you have your first lucid dream and you awaken right away it's quite disappointing and it's easy to feel like giving up if you don't have another one soon. Just don't give up, it may take time, but if you put effort in it, it will eventually come. I know this is sooner said than done, but I have felt like this too, and I guess the majority of other lucid dreamers have also at some point. However, don't get stressed up over it. Sometimes I've felt like I needed a lucid so badly that it just wouldn't come. Putting pressure on yourself is a major setback as well. Try not to compare yourself with other family members who more easily have lucids than you.

Hope this inspires you a bit