[bartread]

It's possible he may not have noticed, or may not have realised that his RHR was unusually high. I mean, in day to day living how many of us are really conscious of what our hearts are doing outside of periods of heavy exertion?

[arandr0x]

120 is an "uncomfortable" heart rate though; you'd feel it at rest, it would somewhat get in the way of concentrating or sleeping. (Although it's easy to dismiss as resulting from anxiety or infection.)