I realise I didn't quite finish my post about determinism last week - I got a little distracted by semantics and trailed off about halfway through. I had two points I wanted to add to that post but I can only remember one of them.
No wait, I totally just remembered the other one. OK - here's a different way of looking at determinism. Think back to a past event (a major event is probably easier here) and look at all the factors that brought it about. The past is concrete, and we can observe how all those factors brought about that event. Determinism simply observes that at any given moment, all those factors exist - it is just the event itself that has not occurred. The present (and therefore the future) is as concrete as the past. We simply do not have hindsight allowing us to observe those factors.
Second point: determinism is irrelevant! Yay! We might not have free will, but by and large that doesn't really mean much. As I've already said, it's not like fate where one event is pre-decided and will occur no matter your actions. Determinism simply says that your actions are decided by the past and will decide the future. Furthermore, the human mind may not have free will but it is still conscious. Enjoy that! It's nigh-on impossible to comprehend all the determining factors that influence your mind and since most of them are subconscious it's not really worth worrying about. Determinism simply disproves superstitious notions like fate, "true love" and divine intervention - just like common sense does.
It's been a long day at work and I can't really think how to end this post, so I'll just bow out. But everyone should go and listen to "Secret Alphabets" by Kasabian.
TL;DR - Just because we can't see all the factors that determine an event doesn't mean they weren't already there, and thus immutable. Also, who really cares if we don't have free will? We're still conscious and that, surely, is what's important.