Would I be infringing if I made a similar work?

Long time ago when I was 5 years old a friend showed me something that I could use as art today. If I made this thing, painting it, would this be infringement? There is something else I would make too. Not copying the actual work, but making my own work, with the same idea.

too vague, need more information

You would have to find out the specifics about the said “Thing” and if it is a trademarked, copyrighted, restricted use or anything of the sort tied to it. Similarly how Disney stuff is labeled “Fan Art” You are allowed to display it but at no point could you sell it or distribute it. So again, check into finding out what the “Thing” may have any ties to or licensing and go from there.

Similar to a little just for fun video project I did about zombies. I seen this commercial ad on YouTube for an actual hardware store. I contacted them via email and by phone to see if it was alright if I used the clip of their commercial in my video. They directed me to the production director that was involved with the production of the commercial and he gave me consent in e-mail allowing me to use the video clip providing it was not for any personal advertising or monetary gain. Having had that written consent then that allowed me to use the clip.
Now there is the typical mentality nowdays of “ehhh Who is going to actually check into seeing if I am authorized or not to use/make/sell this” And sometimes they get by with it and other times they get warnings and other hasty situations they get fines or jailtime for infringement.

So take it as you will.

Call me cynical, but I have to ask: is this yet another “I want to make lots of money with art” question?

It did in fact have somethign to do with making money. But by way of producing an artwork. I decided to not do it, because it was not my idea, 35 years ago. I think it could make some money. But not for me, because it really belongs to someone else.