This section mainly deals with those people who are unsure about whether what they are experiencing is akin to other therianthropes, or just the plain curious.
For some people, their phenotype is an aspect of their personality which comes and goes, or shows itself at different times. For others, the phenotype is a part of who they are, ever present, and just part of themselves. In both cases, therians feel more animal at some times than others, or in some respects, are their animal all the time.
The therianthrope often feels the need to behave in an animalistic fashion, like stretching or lounging around, perhaps wanting to be petted or scratched. They might relax and feel their body gently shift into feeling more like their animal's body than the human body. It might be an impulse or desire to do things which are thought of as "animal" rather than human - for example wanting to chase birds, liking the idea of eating raw meat, running around on all fours...the list is endless, and personal to the therian in question. There is no set way that one "should" feel, but it's usually pretty plain to the therian that it's not the norm for other humans. This is usually the way in which therians become aware that they want to seek out an explanation for the way they feel. Such behaviour is, in normal society, often seen as childish or even deranged, and it is usually confusing for the therianthrope prior to finding out that there are others like themselves. They might feel as though they are mad or delusional. Perhaps we are, but at least we're not alone!
One thing that a therian phenotype does not do is act independantly of the therian themselves - it is NOT a seperate entity, but a part of the person. Therefore, it is not possible to "lose control" of one's phenotype. This is often used as an excuse by some people, most often those who are not truly experiencing therianthropy (e.g. "posers" - those people who pretend to be, or who roleplay as, therianthropes) to excuse bouts of anger or violence. If someone is really losing control of themselves and believe themselves to be animal at this time, this comes under the mental illness Lycanthropy. Although the word sounds similar, Lycanthropy is a serious medical condition in which one loses control of their actions to violence. But, just to make things really confusing, it is possible for the person's phenotype to become more obvious in moments of heightened emotion, for example anger. In normal daily situations a person usually does not conciously behave in a fashion which could be considered animal - it is not considered acceptable by human society. However in these moments, it may subconciously become more apparent and the therian is too consumed or preoccupied by emotion to bother to suppress this. They are still entirely in control of their functions and responsible for their actions, however. Therefore, it is best to be cautious of anyone who tells you that they can "lose control of their wereside" or that it causes them to act violently.
Being a therianthrope does not, above all, make someone special. What makes a person special is who they are, the sum total of all their personality. For therianthropes, being what they are is not a daily consideration in life. It may occasionally come up, it may be something which occasionally makes us muse, but in general we accept who we are and just function as normal. While it may be very interesting to find out you're not alone - it always is - it is important to come to terms with being who you are, and get used to it. You have a whole life of it ahead of you.
Obviously this has but scraped the surface of what being a therian is really like. For the best way to find out a wide range of experiences and to share your own, a community forum is the best place to start out. Care is always best exercised with these kind of internet message boards, and don't be put off if someone takes it upon themselves to attack you. There are good people and bad, as with any community. Use external resources where possible and ALWAYS evaluate what is being said with what you have found at other sources. Make your own decisions, and question others as much as yourself. Good luck - reputable sites can be found in the Links section.