Copied from an old post explaining to a newbie how it would be:

Quote Originally Posted by Coelho
The high can be like this: after a lot of coughing, you start to feel your body is relaxing... your eyes feel like closing a bit, your head feels heavy... you think "i think it does not worked... everything seems SO normal"... and then........

..................oooooowwwwwwmmmmm..... suddenly things become VERY weird... you blink and then "what i was thinking a moment ago?" you forget... you notice the world seems "plane", the vision has lost its depth... the colors seems SO brighter... you can notice minute details of everything around you... like youre seeing the world for the first time... everything seems so new... then you notice a lot of sounds into your head... they are just the sound of things around you, but they seem much louder... and you can percieve details of sound you never realized before... listening music is an awesome thing while stoned...

time slowed down to a snail pace... seconds feel like minutes, minutes like hours... you thoughts are racing... you think a thing and it makes you thing about another one, and this one makes you remember about another one, and so on... you think millions of things in minutes... probably you start laughing madly at this point... everything seems SO fun...
One day, when i have enough patience to sit down and write down all the history of my first time, i will make a better and more detailed description. While this day doesnt come, the description above is the best i have.