I took an elevator but.,

before I start this, I want to make one thing to be clear.

What you wrote is correct, but "make one thing clear" is a common expression.

tThis isn't my story.

I am just trying to be imaginative.

It seemeds like something challenging always happeneds to me, and only me, like something unusual traffic dragging my leg not tokeeping me from makeing it to work ion time.

sSo, like the other days, I was already ready to say, "I'm late because of traffic," when I got on the office as I just got inside the building.

hHonestly, I had like 5 minutes room, but this early given up was reasonable becauseto spare, but unfortunately a nightmare was waiting for me.

I don't understand the middle part of this sentence "this early given up was reasonable because "

Well, the building was so old that there were only a couple of lazyslow elevators takinghat take me so long all the time.

mMost of time, it was all because there' are plenty ofmany people getting in and off on every floor.

Anyway, over there, people were waiting forto get in to the elevator that just stopped to get in.

If I took it, it mustwould be a life saver.

sSo I rushed, and luckily I got in with the others.

bBut because my mind was fully takendistracted by being late, I didn't realized that this elevator wouldn't go to the floor whichthat I had to get off on.

aAnd I didn't know that fact until the door was completely slided closed and I hit the button to the floor.

oOn my first try, I pressed the right floor, but Iit didn't work.

Then, I thought I made a mistake, but asand I giave it thea second try, but it still didn't work.

aAnd at the moment it hit me that I was stuck in the wrong oneelevator that wereas designated tonly for lower floors and I was really late.

bBefore I start this, I want one thing to be clear.

tThis isn't my story.

I am just trying to be imaginative/creative.

This morning I was about to be running latealmost was late for work.

It seemed like something challenging always happeneding to me, only me like somethingas if unusual traffic was dragging my leg not to make it to work ion time.

sSo, like the other days, I was alreadybout ready to say "I'm late because of traffic" when I got on the office as I just got inside the building.

hHonestly, I had likeabout 5 minutes room, but this early given up was reasonable because a nightmare was waiting for mto spare.

Well, the building was so old that there were only a couple of lazyslow elevators taking me so long all the time.

mMost of time, it was alltook a long time to go up because there' were plenty of people getting in and off on every floor.

If I took it, it musthad taken it, it would have been a life saver.

sSo I rushed, and luckily I got in with the others.,

[the next sentence should go here]

but because my mind was fully taken byI was preoccupied about being late, I didn't realized that this elevator wouldn't go to the floor which I had to get off.

and I didn't know that fact until the door was completely slided close and I hit the button to the floor.

oOn my first try, I pressed the right floor, but I didn't work.

and aAt the moment it hit me that I was stuck in the wrong one that werelevator, the one designated to lower floors, and I was reallyunning late.

I took an elevator but.

If you want to have the title tell the reader that something went wrong when you took the elevator and get them to read on, you could also title it "I took an elevator, but ..."

bBefore I start this, I want one thing to be clear.

tThis isn't my story.

I'm just trying to be imaginative.

This morning I was about to be running late.

It seemed like something challenging always happened to me, and only me, like something kind of unusual traffic dragging my legcausing me not to make it to work in time.

I'm not sure what the last part means. "Dragging my leg?" is this related to the traffic or something different?

sSo, like theon other days, I was already ready to say "I'm late because of traffic" when I got ton the office as I just got insideentered the building.

hHonestly, I still had like 5 minutes room, but this early given up was reasonable because, but a nightmare was waiting for me.

Well, the building was so old that there were only a couple of lazy elevators taking me so long all the timeand they always took so long.

mMost of time, it was all because there're plenty of were so many people getting ion and off on every floor.

Anyway, over there, people were waiting forto get into the elevator that had just stopped to get in.

If I took it, it mustwould be a life saver.

sSo I rushed, and luckily I got in with the others.

bBut because my mind was fully takenoccupied by being late, I didn't realized that this elevator wouldn't go to the floor which I had to get offI wanted.

Or "the floor where I wanted to get off."

aAnd I didn't know that fact until the door wasslid completely slided closed and I hit the button to the floor I needed.

oOn my first try, I pressed the right floor, but Iit didn't work.

Then, I thought I made a mistake, but as I giave it thea second try, it still didn't work.

aAnd at the moment it hit me that I was stuck in the wrong one that werelevator, the one designated tofor lower floors and I was really was going to be late.

The last part is just because this order makes it clearer that it's a realization, as opposed to just saying "I was really (very) late."

tThis isn't my story.

I was just trying to be imaginative.

This morning I was about to be running late.

You can say "I was running late".

It seemed like something challenging was always happeneding to me, and only me like somethingas if there was some unusual traffic dragging my leg not to make it to work in time.

sSo, like the other days, I was already ready to say "I'm late because of traffic" when I got on the office as I just got inside the building.

hHonestly, I had like 5 minutes roomto spare, but this rearlyson was given up wasearly as a reasonable because a nightmare was waiting for me.

mMost of time, it was all because there're plenty of people getting in and off on every floor.

If I took it, it mustwould have taken it, it would have been a life saver.

sSo I rushed, and luckily I got in with the others.

bBut because my mind was fully taken by being late, I didn't realized that this elevator wouldn't go to the floor which I had to get off.

and I didn't know that fact until the door was completely slided closed and I hit the button to themy floor.

oOn my first try, I pressed the right floor, but Iit didn't work.

Then, I thought I made a mistake, but as I give it the second try, it still didn't work.

and at theat moment it hit me, I realized that I was stuck in the wrong one that were, and the button would work as it was designated to lower floors and I was really late.