そう思ってもいいよ。

so; really; seeming; appearing that; seeming that; looking like; having the appearance of

to think; to consider; to believe; to think (of doing); to plan (to do); to judge; to assess; to regard; to imagine; to suppose; to dream; to expect; to look forward to; to feel; to desire; to want; to recall; to remember

too; also; in addition; as well; (not) either (in a negative sentence); both A and B; A as well as B; neither A nor B (in a negative sentence); even; as much as; as many as; as far as; as long as; no less than; no fewer than; even if; even though; although; in spite of; further; more; again; another; the other

good; excellent; fine; nice; pleasant; agreeable; sufficient (can be used to turn down an offer); ready; prepared; profitable (e.g. deal, business offer, etc.); beneficial; OK

indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!