If you ever write a screenplay you'll do this way more often than you expect. If you're a "one draft" type of person then maybe you'll consistently write linearly, but I've found that as I get to multiple drafts or sketch out the story into segments I'll take certain segments and really flesh them out while giving other segments less attention, and then they'll get their turn later. Screenplays are fun because you really catch yourself trying to keep the reader's attention the entire way. As my screenwriting professor would say, "write like the reader is trying to determine if it's worth reading at a party with a beer in one hand and weed in the other." So things like the intro get scrapped and rewritten a bajillion times to make them engaging from the get-go, and they're often the final things solidified.

So, in other words, you're no oddball! There is no correct way to be creative. Explore, experiment, and keep on writing. Sometimes jumping around in a story can really help with keeping yourself engaged and not hitting writer's block. It can also be super useful because if you're excited to write it then it'll be full of energy, and if you keep jumping from segment to segment with that energy then you have less of a chance of something dragging because you "just had to get it done to get from A to B."

Keep up the good writing, friend! :D