Ever decided to change the way people know you? To use an alternative derivation of your name? Don’t. At least, try to avoid it. Unless you act like a fascist about it to the people you already know, it’s just too much hassle. New people who meet you will be okay. But anyone who already knows you will still know you by the old name. When you ring them up, you’ll be torn between opening with "Hi, it’s Daniel" or "Hi, it’s Danny."
Yes, I am a sufferer. I don’t mind that a few people that I’ve known for more than ten years call me Danny. I just decided I didn’t like it anymore. Okay, to be honest, I first used Danny when I started primary school, because it was easier to spell than Daniel. So ten years ago I switched. I reckoned Daniel sounded more grown up. <Insert the shoulder shrug of someone who will not vouch for anything they did during their childhood years here>
Of course, being known by different names makes it easier to remember people who re-introduce themselves to you after a long period of time. But the ultimate solution for names would be, when introduced to someone, to introduce yourself as having exactly the same name. It goes something like this:
PERSON: "Hi, I’m Mike Cardigan."
YOU: "Oh really? What a coincidence, I’m Mike Cardigan too!"
PERSON: "Oh really, that’s amazing…" (etc)
<10+ YEARS LATER>
PERSON: "Mike Cardigan! G’day mate, I haven’t seen you in years!"
YOU: "Oh hi, how are you! Mike Cardigan, isn’t it!"
PERSON: "Yes it is! You remembered!"
YOU: "Well, I never forget a face… Especially with the same name as mine…" (etc)