When I'm in a "neutral state" - not sick, injured, etc. - and I focus on my body's senses, I pretty much always notice some kind of ache, tenseness, stomach pain, itchiness, or some other uncomfortable feeling that I'm generally able to ignore when I'm not not fixating on it.
This reminds me that it does take work to tune into pleasure (I myself need to put more effort into it).
Have you tried observing the feeling that comes up when you come home from work and then finally sit (flop down) down onto a couch...ahhh what a relief.
Or...on a cold morning jumping into a nice warm shower...ahhh how good the warmth is.
Or...going for a jog and feeling a bit of a runner's high...or a brisk walk feeling the body breathing smoothly and functioning well.
As for sitting still and feeling pleasure, that takes work, and Buddhist meditation is a good way to find it (also it depends on the teacher and type of meditation) -- There isn't any evidence that Epicureans did meditation (but Torquatus explains the meaning of Cryssypus' hand which could be seen as very similar to meditation - I'll look for that thread and edit in the link when i find it).