Branches arise from buds which are found in the angle between a leaf and the stem. These are lateral buds. There is a bud at the tip of the stem, the apical or terminal bud, and this bud supresses ths development of the lateral buds. If you like technical terms, this effect is called 'apical dominance'. Genetics and/or time over ride this effect and lateral buds develop into branches. We manipulate this phemomenon when we prune a shrub to make it 'bush out'. The effect also helps in diagnosis! If the lateral buds unexpectedly start to develop, it MAY indicate that the terminal bud is dying or dead.
I did have to look up some stuff while doing this and I wish to thank you for helping me to keep on my toes.
Cheers!

Thanks for the well written response. I am reluctant to pinch off the main bud ofcourse, but I will consider doing so once I decide to repot. Thanks!