Try and have as much fun as you can! I know the PhD can be up and down, but I had a lot of fun in my PhD, by knowing people, and discussing science with them, and also simply with lab work. Try and be open to that.
There’s a relatively high amount of work involved – you have to put the work in. You have to be curious, to discover, to go read. It’s never been a 9 to 5 since I started my PhD, but I think that relates to the fun, because if you consider it fun, it’s not really so daunting to go to the lab and do a reaction at 8pm or whatever.
I think it’s very valuable to try and understand the different disciplines. So I’m currently in an engineering department, I’m a chemist, and I learned biotechnology in my postdoc. I think it’s very important to understand other people, and to respect what they do, and to be a bit humble about it. You might know all the engineering in the world, but there are so many things you don’t know, and cool ideas can come out if you think outside your discipline.