First off, Congratulations model citizen for making good choices in life.

Now, to answer your question: inhaling the contents of a compressed air can gives a powerful yet unnerving high. It takes your mind to a place that I latter compared to hell. Yet the effect only lasts 30 seconds, which quickly beckons another hit. Before long you are at the bottom of the can and feel a sadness.

Long term abuse caused me to vomit, pass out, and I would slip out of reality. I would lose 10 minute segments of memory and even have verbal arguments with people not there.
It was a cheap high and a cheap escape. Funny thing is, it was never a pleasant experience, and yet I kept going back.

Fast forward several years. I don't even smoke or drink anymore, I just find reality has enough to offer.

TL;DR: Don't do drugs, drugs are bad.

If you're looking at that picture and are going "how is that relevant to the picture above" then congratulations! You are a model citizen that has made wonderful decisions in life.

If you looked at that pic and laughed/understood the relevance, than there is a very good chance that you(like me) have made a poor decision at least once(or dozens in my case)