Things you'd tell the newly qualified you

I've just started a blog and, a few weeks in, I realise I am, in essence, writing a long letter to the 23 year old newly qualified me, just starting his new career in industry.  I'd be very interested in suggestions for things that you might have told the less experienced version of yourself!

If you can spare the time, I'd be grateful for any feedback on what's already there on http://www.dsmann.co.uk/blog/  

Thanks in advance.

David