The old man, like myself, had so healthy an upbringing (10)
I believe the answer is:
methuselah
'the old man' is the definition.
(thesaurus)
'myself had so healthy an upbringing' is the wordplay.
'myself' becomes 'me'.
'had' is a charade indicator (letters next to each other).
'so' becomes 'thus' ('thus' can be a synonym of 'so'**).
'healthy' becomes 'hale' ('hale' can be similar in meaning to 'healthy').
'an upbringing' says the letters should be written backwards.
'hale' back-to-front is 'elah'.
'me'+'thus'+'elah'='METHUSELAH'
'like' acts as a link.
(Other definitions for methuselah that I've seen before include "One very old" , "Old man of the Bible" , "Old Testament patriarch (very old when he died!)" , "able to hold a lot of drink" , "He lived 969 years (Gen.)" .)