For over five decades now, we are investigating the physical processes driven by stellar bars in disc galaxies and their effects on galaxy evolution. In this talk, I will present my view on what we have learned so far, with a focus on processes that build the main stellar components in the central regions, sometimes referred to as ’pseudo-bulges’. I will also show recent results using MUSE data that point out the formation redshift of the first robust bars and the cosmic epoch when the first dynamically mature discs were established. I will conclude by making an attempt at clarifying misconceptions and presenting outstanding open questions.