I've had asthma for as long as I can remember, so I don't remember my first attack. I just grew up like that, being awakened during winter by attacks of cough and shortness of breath, until I received controller medications that settled it.
I do remember the first asthma episode that was worse than what I had been used to. I was twelve, had it when I tried to run in my gym class. I was forced to stop in the middle, and once stopped it became instantly worse and I was quite afraid. I remember struggling to catch my breath, wheezing out loud, and my chest was so tight that each breath was painful to take. Luckily it resolved on its own as I had no inhaler around.
Next episodes weren't as frightening because I was prepared.