The bass guitar was the first instrument I really applied myself to and achieved any skill with. I still play the bass now and then, as it's a skill that never leaves you, and is an excellent way for any guitarist to find variety in their musical life or career. Bass is the fundamental basis of all music, as its main job is to play the most important notes in music- the root notes. Therefore it is an excellent way to start learning from the ground up.
    The learning curve of the bass guitar is quite easy, and it has an excellent work to payoff ratio. So the emphasis when playing bass is usually on the fun part of playing. And since the strings are much thicker than a guitar's strings, and you play only one note at a time, it quickly strengthens your fingers to the point where learning to play the guitar is quite an easy transition to make (which is precisely what I did!). Most bassists find they can easily learn to play a little guitar, and vice versa. If you can't decide which instrument you want to play, bass is an excellent starting instrument, and lays a foundation of strength and basic musical concepts that make learning other instruments even easier.
    Paul McCartney of the Beatles, Sting of The Police, and Flea of The Red Hot Chili Peppers are all examples of well- known and excellent bassists. If you've ever seen yourself in their shoes, rocking out or laying down a funky bass line, give bass guitar a try!