Meditation is just like yoga. The
more you do , the softer and more flexible your body
become.
The keyword is perservance.
Of course there will always be exceptional cases where the
person is not suitable to push on when it is clearly not suitable.
In that case, you can still do your mediation sitting on a chair
(which the ancient taoist sutra suggests that it is equally
good).
When we do the three steps one bow
or when we do the full body prostration , we will find it very
difficult at first. Perspire, body aches , panting for example.
However if we persist, we will definitely find it much easier the
next time, our body more adapted to the exercise ( which in a way
is good for physical health).
There is actually no hardship in
practise once you get used to it. It is only in the mindset of
beginners , laypeople when they just embark that it is quite
suffering. In that case, if one meditated and see all the
sufferings in one's past-lifetimes, one will realise that the best
way to end it all is to be liberated from the rebirth
cycles.
Yes, the physical can be "Now" but the memories of pain can be
in your conscious from previous lifetimes.
Makes sense...especially from physical point of view.
You mentioned, "...the memories of pain can be in your conscious
from previous lifetimes" - in what form does this come in in our
current lives? i.e. how do we recognis these pains from our
previous lives?