Honestly? I'd be absolutely horrified. It's all well and good to say "I know the outcomes of every major sporting event, what companies will take off, and all dem bitcoins" but there is so much that isn't thought about in these scenarios. In my case, I have a life I am very very satisfied with. I have a wife I adore and a job I love and we're talking about starting a family. If I was suddenly 5 again, all of that would be gone. All the things that I value most in life would suddenly be gone. I would dedicate my life to doing everything I had to do to get back to exactly where I am now, and if you stop and think about it, that's a really shitty thing to have to do.
Past that, I'd then have to grow up with all the knowledge that I have now, knowing what events have taken place. My dad died in an accident when I was 13, so i'd probably ask him to stay home from that trip, but i'm just a 13 year old kid so he probably wouldn't listen, but then again, who knows what my life would be like today if he was alive. That event hugely defined who I am today, and maybe me and my wife wouldn't be together if that hadn't changed the path of my life. I might have to let him die all over again as to not risk my current future. That's not a decision I want to make.
Then I'd meet my wife again when I was 15. I met her when I was 15 but we didn't start dating till I was 24. I have no idea what are the major crossroads decisions in my life between those ages. Anything I do differently could drastically change the outcome of my future and I wouldn't be where I am now. So I would have to be extremely careful to make every exact decision that I made in my life exactly the same, because I don't know which of those decisions could drastically change something else. The stress of that would be absolutely unbearable.
Let's say that I manage to do all of that and my future is set, I still have to spend an entire decade in my wife's life, watching her date other people, watch her go through every horrible thing that I now know she was going through and not be able to do a damn thing about it, because as we've discussed earlier, any single change in anything could majorly change the outcome of our lives. I can't even act like I know, I just have to pretend I don't care. I can't just walk up to her and start spilling to her about these very intimate moments of her life that she hasn't shared with anyone. That would freak her the fuck out and she'd probably never talk to me again. I just have to watch her suffer, watch her date that guy that I know will abuse her, watch her mother's treatment of her send her into a depression that will take years to get over. I don't know if I have the strength to do that. I'd also have to go through all the shit relationships I went through knowing that none of them are fulfilling and just waiting a decade for what I know will actually make me happy, once again making sure I make every regretful decision again the exact same way as to not risk my eventual happy future.
Now if by some miracle I manage to pull this all off, I imagine the stress of it all will age me horribly, and i'd end up dying earlier than I would have otherwise. Sure i'd have money, but I don't think the suffering that I had to go through over the last 25 years would be worth it.