Legend has it that the 75 bus route was intended as the final punishment in the various circles of Hell by Dante but even he was too afraid to put the idea in writing. No such fear was shown by Dublin Bus however when they inflicted this god awful route upon the good and unwitting people of Dublin.
The route is long (who actually needs a bus to go from Dun Laoghaire to Tallaght??), changeable (does anyone know in advance when it decides to go through Sandyford?) and rather tedious (time would be better spent watching grass grow). It is due to these issues that the bus takes approximately two to three eons to get from A to B.
Fellow passengers can also vary. People have at various times let their dog have a poop on the bus or discussed the merits of hitting their mate over the head with a bottle.
If at all possible do attempt to not use this bus. Use Dart, luas, bobsleigh or llama to get you from place to place and save yourself the hassle etc. Life will be easier that way. read more