You're assuming that Clegg has expressed his true aims in public. Given his record of spectacular outright lies - such as the famous u-turn on tuition fees, or the way that he denied being a Young Conservative at Cambridge, in spite of the evidence - it's possible his affable victim-of-circumstance brand is just a cover for someone who is essentially manipulative and dishonest.
Given the successful spoiler/enabler role of the LibDems in UK politics, there's a good chance he doesn't think of his record as one of failure on any level.
Interesting, he has already deleted all of his tweets, including the anti-Brexit ones - not quite the action of the absolutely committed anti-Brexit campaigner he claimed to be.
(To say "FB wouldn't let him keep them" misses the point. Someone who was genuinely committed to stopping Brexit would never accept a job which might conflict with keeping them.)