I assume that 95% effectiveness means there is a 5% chance a vaccinated person will get infected and sick just like anyone who hasn't had the vaccine. There are reasons why the number in practice will be worse: vaccinated people will be more confident to take fewer precautions compared to people in the clinical trials (who did not know if the vaccine was effective, or if they received a placebo). The clinical trials did not try to detect asymptomatic infections. People who volunteer for the trial may be healthier than average. NYT explains the difference between efficacy and effectiveness, adding that the FDA might have approved a vaccine with even 50% effectiveness.

On long term consequences, I've also seen anecdotal reports, but when I click through to the data in studies of long-term effects, the "young people" always turn out to be of retirement age.

I got the flu in early 2018 and I would be willing to pay a little for a vaccine that reduces my risk of getting sick and spending a week in bed, and possibly spreading a virus that kills many people every year. Half an hour at the pharmacy for a "free" flu shot is the smaller cost, the bigger (and probably more effective) effort is habitual germophobic practices. For the new vaccine, while supplies are limited I think they should be reserved for people at greater risk than me.