To an outside, sober observer, someone high on any drug looks weird. Don't do drugs in front of people who don't take them, you will only ruin your reputation!
As to the long term effect on you life, you become a drug-seeking person. It is worse if the drug is illegal and difficult to procure because all your life resolves around strategies to procure it.
If the OP's question was about the combo C + ethanol, this has been discussed before. South Americans usually combine lines with shots of brandy. But they have access to pure C and do small lines. If you binge on heavily adulterated C (like you will outside SA these days), your combo is C + ethanol + (speed) + (amps) + (ephedrine) + ??
On a more general note, what is certain is that the war-on-drugs can turn whole human Societies into groups of repressive psychopaths. This is why drug users should never own up to accusations of "being psychopaths" without first calling upon Society to clean its act. If you want to take C and have insane thoughts running through your mind in the privacy of you own home, that should be for you to decide and not for overweight rednecks with ugly kids.