I don't think SC WIS is a troll. I think he "is" a 15 year old, I have had two 15 year olds but they grew up.

SC WIS, one thing life teaches us the older we get are things like the world does not revolve around "us".
Why wouldn't someone stop to help me? You have gotten a lot of responses and, now you know, for a flat tire, they shouldn't have to stop. Be self sufficient, as much as possible.

Back to the scenario of a flat tire. If you had a spare tire, and you had your wheel off of your bike, and as cyclists passed you, you stood there (assuming you did not have the skill yet) with wheel and spare raised in the air, saying "Help please" I am almost certain someone would stop to help. So, the first step to self help is to appear you are trying to help yourself.

Step two, we already have seen, is learn to do it yourself. Google and You Tube. We didn't have those things when I was a kid. Typically you watched someone else do it, then you were on your own.

One time I was cycling down a MUP, a guy was pushing a 26" Mtn Bike with a flat, as I approached he asked "Gotta spare tube?" I kept going, didn't stop, and just said "No, sorry". I have a 700 tube with me, not a 26". He may have thought me rude, but, without the proper sized tube, what can I do for him?

Bottomline, be prepared, and look like you are at least trying. I am much more likely to stop and assist if I can clearly see your issue and see there is a clear solution.

I'll repeat what others have said, get a tube, get tire levers, and a small compact pump.
If you don't have $ for those, go find some work to do to make enough to buy them. Mow someone's lawn, shovel some snow, clean someone's yard....something.

Being self sufficient also means having a "Can DO" attitude and be your own problem solver. Excuses are unproductive.

Q: Do you know how to change a tire right now? if "no" is your answer, change screens, go to You Tube and type "change a bike tire" Watch a few videos.

Good Luck with everything.

You will stand a better chance in life, getting help, if you appear to be helping yourself.