NOT!!!

Depends. First the bass has heavy strings which hurt more than guitar strings. You will also have to have great timing and be able to play well with a drummer for most musical styles. If you want to do simple rock stuff it is reasonably easy. Root note patterns like a great deal of punk (Sex Pistols and so on) are pretty easy. Harder rock can start to get trickier. There may be faster semi-quaver patterns and so on which you will need to start developing you right hand technique for. But most rock is fairly easy. Then if you are serious it gets hard and fast. You need to know your scales and arpeggios in order to move around the instrument easily. Guitar is easier as you have the extra two strings but we have to make far more positional changes for, say, a 2 octave arpeggio and so on. If you want to play like Flea or Jaco Pastorius you are going to have to put in a great deal of work. There are also a fair few techniques to master: chords, tapping, harmonics, slap even using a pick (which I can't stand but sometimes you get asked to do it). So it really depends what you want to do. Same with any instrument. If you want to just strum chords on a guitar it ain't hard or a simple backbeat on a drum kit is dead easy. But being Jimmy Page or Max Roach is going to tax you.

I think that learning the bass guitar is really easy if you can already play a guitar, because the guitar has six strings and the bass has four. Also if you can play the piano, you should be able to read treble clef(which are what guitar players use) and bass clef(which bass guitar players will use). If you don't read bass clef it should not take you long to pick it up.

It's as hard as you make it. Learning the basics of any musical instrument is fairly easy. If you want to get GOOD, then expect a lot of hard work. However, the key to learning an instrument well is repetition. Truly and utterly ASININE amounts of repetition. It's about burning in muscle memory and training your ears. Just because you can play a scale or whatever ONCE doesn't mean you know it. Being able to play it 100 times without a mistake means you know it OK. Being able to play it flawlessly in front of an audience EVERY TIME means you really know it. But really, if you practice a lot and don't get discouraged, you will make great progress and have a lot of fun doing it. :)

I taught myself how to play almost two years ago. I love it. I believe if you have it in your heart to want to learn, you can. Marguerite :basses can gave more than 4 strings! ;)