I've been in a few, but keep in mind I speak as a woman and almost always as a lesbian (I did have a few boyfriends, especially in my teens, those these were often superficial). I'm only going to speak in general terms, too.
I guess it starts out as like a "honeymoon phase" where passion is high and you become obsessed with your partner (which is hopefully returned, or it can be bad, even if the one obsessed doesn't become a stalker). At the same time it can be kinda tense because you try hiding your flaws a lot more, though even when discovered at this phase the flaws are likely to be seen as cute rather than annoying (that doesn't mean they'll remain cute as the relationship progresses). Of course some flaws can be too bad to overlook, and you may not notice them for awhile...like you may find yourself wondering where the hell all the food is going, why there's suddenly too much garbage, and why your grocery bill is through the roof before you realize your partner is bulimic. Sometimes your partner will even hide STDs from you. And it's a safe bet that a partner will have a dark side (though you should remember that it can be challenging living with you and your quirks, too). For this reason you should avoid moving in until you get to know them better, IMO, though I've broken this rule quite a bit and it's turned out ok. But when you move in together too soon and find your partner has a violent temper or major drug problem it can be very hard and expensive to separate (as well as dangerous).
One important thing, IMO, is not to neglect your friends though you may want to spend all your time with your "better half." You'll be glad you kept up relations once you come down from the high of passion and they may give you a much needed reality check at times (of course they can be a cause for jealousy, too, though I think it's good to find out about an intense jealous side of a partner sooner rather than later). In a worst case scenario they can even help you if the relationship takes a violent or dangerous turn. Having outside interests can also keep you interesting. And there is too much of a good thing: too much of one person can lead to a loss of passion or even alienation, like children who gorge on candy at Halloween get sick at the thought of anymore and have to hold off for awhile. While being together is one of the best feelings in the world (well, usually) there's a point of diminishing returns and if you do it too much feelings of being loved can turn into feelings of being smothered. (Also, they can start wearing your clothes. :tongue
If one or both are in the closet it can be hard, especially if you want to share about your relationship (as many do), so you have to be silent or be careful with your pronouns. And keeping a picture of your partner on a desk is out. You have to keep track of so many little details and lie to people around you and it can be hard to like talk to your partner over the phone, especially when others are around. It's not fun to live in secrecy and fear while others around you get to live openly and honestly and I think only a few are thrilled with such secret relationships.
Anyway, that's off the top of my head. I get the impression that your English, while good, isn't perfect, so please don't hesitate to ask me what a word means or to repeat a sentence with simpler words.
mile:
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