Now I bashed as a teenager and not an adult.
In fact I think this is really the best for your sanity, although I often do regret spending the ned time I did on bashing. Why? Well I could have had a much better spring start into my later hobbies of cycling and sailing in terms of fitness, experience and not in the least, social standing!
Bashing is physically bad: a lot of sitting on your rear end, diesel fumes, take away food.
Bashing was psychologically bad: how can you live with your favourite locos being (inveitably) taken off passenger routes in favour of plastic and then cut up?
On the pluss sides though:
You learn about geography and logistics of travel. You learn about the railway.
It is a very egalitarian sport which makes social contact across social classes: well apart from scousers and maccelsfield types who had too many drunks, vandals and dicks in their ranks imho...
As a teenager you get a great feeling of freedom within some safe environment of the railway staff and the commonality of other bashers.
You learn a lot about mechanical things, about HSE and about planning of projects.
You get to relax a lot.
It was, and probably is, fun.