The biggest question is: Do you prefer working with humans or working with computers?

If you prefer working with humans -- e.g. you had/ve a lot of (girl) friends; you prefer late drinks parties instead of drilling deep into some esoteric computer problem; you are not super intrigued by topics such as compiler design, operating system and such -- then you shouldn't have a lot of problems. After all the baby is just one of the humans you are going to interact.

If you prefer working with computers, well, let me say that judging from my own experience it's going to be a huge challenge to you -- so challenging that this is probably the biggest challenge unless World War 3 happens -- it has been that bad for me. I'm going to focus on the mental shock and preparations for the negatives. The others are easy, and you probably don't want me to repeat the up sides.

If you don't know which type you are -- try to figure out if you are REALLY REALLY excited about being a father. I mean REALLY REALLY REALLY excited, like getting a new life. If not, you are going to need the following information nevertheless. In my case, I actually didn't feel anything when the baby was born. No positive or negative feeling, nothing at all. Maybe I'm a weirdo.

Babies are the opposite pole of computers. It can't be bargained with, it can't be reasoned with. It doesn't feel pity! Or remorse or fear and it absolutely will not stop! In the best case, babies are black boxes that you can poke with some input and all kinds of output fall out. In the worst case, they output regardless whether you poke them or not.

Where should I start? Ah yes -- first, you are going to lose a lot of sleep, perhaps forever. But I guess you already know that, so I'll skip it. Just remember -- however mentally prepared, you won't get use to it in the first month. But however bad you feel, you are going to get used to it after 6-12 months.

Secondly, you are going to lose a lot of free time, again perhaps for a long long time. This is way more serious than losing sleep, if you prefer work with computers. This basically means you are NOT going to have much refresh after work. You will always be on high-tension because you don't have the time to chill down with your lovely computer. The situation will gradually improve when they reach age of X -- X depends on your parenting style -- for me it was past 3 but I still don't think it's enough. I'm hoping to get most of my free time back when they reach middle school and start to resent me.

By losing a lot of time, you also lose hobbies and work. This is less for the father than the mother, who is usually the central figure of parenting for the first few years. Nevertheless it still hits the father too. You are basically stuck to one place, one career path and even one position -- and you definitely won't want to lose your job! By having a baby, you are turning yourself into a better clog of the machine that is called society.

The natural, scientific conclusion of the above is depression. I actually recommend book a few sessions with a therapist right now -- because I know you probably going to be depressed. You can't fight it alone. You are going to do bad things if you let it take you. Best case, you recover naturally in a couple of years when you get used to the situation. Worst case, well I don't know what is the worst case but you can imagine. I was lucky to recover without a therapist, but I still explode to anger occasionally for whatever reason.

What is worse is that people, including your wife and your parents, are not going to understand you. Your wife is most likely bathing in the excitement of being a mother, and your parents are probably excited about the continuation of their genes and one more toy to play with. It's a taboo to admit that you don't enjoy your parenting life, and it's almost a crime to admit that sometimes you hate it and want to leave it behind forever. You are alone in this. Actually -- ironically, only the baby is on your side as he/she loves you without a condition.

Good luck.